Area of Real Estate Property Area of Real Estate Property Granted, Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Document Type Document Type Commitment And Contingencies [Line Items] Commitment And Contingencies [Line Items] Commitment And Contingencies [Line Items] Other (expense) income, net Total other (expense) income, net Other Nonoperating Income (Expense) Conversion of operating partnership units (in shares) Stock Issued During Period, Shares, Conversion of Units COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Total interest costs incurred Interest Costs Incurred Related Party [Axis] Related Party [Axis] Change in accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Future Time Period After 12-31-2021 Future Time Period After [Member] Future time period after. Total Revenues Total Revenues [Member] Total Revenues [Member] Segments [Axis] Segments [Axis] Vested, Weighted Average Grant Date Fair Value (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Fair Value, Inputs, Level 3 Fair Value, Inputs, Level 3 [Member] Proceeds from the sale of marketable securities Proceeds from Sale and Maturity of Marketable Securities Aviation expense Related Party Transaction, Expenses from Transactions with Related Party Senior Guaranteed Notes, Series D Senior Guaranteed Notes, Series D [Member] Senior Guaranteed Notes, Series D [Member] Limited Partner Limited Partner [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Accrued leasing commissions Increase (Decrease) Accrued Leasing Commissions Change in accrued leasing commissions LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Lease extension option period Years Lease Extension Option Length Years lease extension option length. Unsecured line of credit, net Line of Credit [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Dividends declared and paid (noncontrolling interest) Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders DERIVATIVE AND HEDGING ACTIVITIES Derivative Instruments and Hedging Activities Disclosure [Text Block] Security Exchange Name Security Exchange Name Interest capitalized Interest Costs Capitalized Adjustment Less: Income from operations attributable to unitholders in the Operating Partnership Minority Interest In Continuing Operations Income Loss Operating Partnerships Minority interest in continuing operations income (loss) Operating partnerships. OPERATING INCOME Operating Income (Loss) Operating Income (Loss) Debt issuance costs Payments of Debt Issuance Costs Nonvested, Beginning, Weighted Average Grant Date Fair Value (in USD per share) Nonvested, End of Year, Weighted Average Grant Date Fair Value (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Variable Rate [Domain] Variable Rate [Domain] Gain on derivative settlement Derivative, Gain on Derivative Variable Rate [Axis] Variable Rate [Axis] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Line Of Credit Future Time Period [Domain] Line Of Credit Future Time Period [Domain] Line Of Credit Future Time Period [Domain] Commitments and contingencies (Note 11) Commitments and Contingencies ASSETS Assets [Abstract] Wbw Hotel Lessee Llc Wbw Hotel Lessee Llc [Member] WBW Hotel Lessee LLC. Accounting Policies [Abstract] Accounting Policies [Abstract] Entity Address, State or Province Entity Address, State or Province Vested, Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Cash paid for amounts included in the measurement of lease liabilities Operating Lease, Payments Sublease income Sublease Income Description of variable rate basis Debt Instrument, Description of Variable Rate Basis Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Accumulated dividends in excess of net income Retained Earnings (Accumulated Deficit) Secured notes payable, net Secured Debt 2021 (six months ending December 31, 2021) Lessor, Operating Lease, Payment to be Received, Remainder of Fiscal Year Contributions from American Assets Trust, Inc. Payments related to Partnership Contribution Payments related to Partnership Contribution General partners' capital, units outstanding (in shares) General Partners' Capital Account, Units Outstanding Right-of-use lease asset, net Operating Lease, Right-of-Use Asset Repayment of unsecured line of credit Repayments of Lines of Credit Repayments of Lines of Credit OTHER ASSETS Other Assets Disclosure [Text Block] Other comprehensive gain - change in value of interest rate swaps Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Early extinguishment of debt Early extinguishment of debt Gain (Loss) on Extinguishment of Debt Held for development Land Available for Development 2022 Lessee, Operating Lease, Liability, to be Paid, Year One Lease income Lease Income Hotel management agreement default penalty factor of previous twelve months of management fees in twelfth year of term Hotel Management Agreement Default Penalty Fact Or Of Previous Twelve Months Of Management Fees In Twelfth Year Of Term Hotel management agreement default penalty fact or of previous twelve months of Management fees in twelfth year of term. Cash paid for income taxes Income Taxes Paid EQUITY: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] 2025 Lessee, Operating Lease, Liability, to be Paid, Year Four Hotel management agreement default penalty factor of previous twelve months of management fees in thirteenth year of term Hotel Management Agreement Default Penalty Fact Or Of Previous Twelve Months Of Management Fees In Thirteenth Year Of Term Hotel management agreement default penalty fact or of previous twelve months of Management fees in thirteenth year of term. Other liabilities and deferred credits, net Total other liabilities and deferred credits, net Deferred Credits and Other Liabilities Schedule of Capital Units [Table] Schedule of Capital Units [Table] Other Other Real Estate Rental Revenue Other real estate rental revenue. Prepaid rent and deferred revenue Deferred Revenue Hedging Designation [Domain] Hedging Designation [Domain] Lease cost Lease, Cost Common stock, par value (in USD per share) Common Stock, Par or Stated Value Per Share Acquired Finite-Lived Intangible Assets [Line Items] Acquired Finite-Lived Intangible Assets [Line Items] Stock-based compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Document Information [Table] Document Information [Table] Equity [Line Items] Equity [Line Items] Equity [Line Items] Construction in progress Construction in Progress, Gross Hotel revenue Revenue from Contract with Customer, Excluding Assessed Tax Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Measurement Frequency [Domain] Measurement Frequency [Domain] Net income Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Number of calendar months termination fee is based Calendar Months Calendar months. Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Proportion of total revenue provided by retail or office tenants (as a percent) Concentration Risk, Percentage Rental expenses Total rental expenses Cost of Other Property Operating Expense Board of Directors Chairman Board of Directors Chairman [Member] Statement [Line Items] Statement [Line Items] Commitment And Contingencies [Table] Commitment And Contingencies [Table] Commitment And Contingencies [Table] CAPITAL: Partners' Capital [Abstract] Thereafter Lessor, Operating Lease, Payment to be Received, after Year Four Lessor, Operating Lease, Payment to be Received, after Year Four Beginning partners' capital account (shares) Ending partners' capital account (shares) Partners' Capital Account, Units Term of debt instrument Debt Instrument, Term Derivative Instruments and Hedging Activities Disclosures [Line Items] Derivative Instruments and Hedging Activities Disclosures [Line Items] Leases Lease Agreements [Member] Statement [Table] Statement [Table] Proportion of hotel occupancy gross revenue paid for program fee (as a percent) Percentage Of Hotel Occupancy Gross Revenue Paid For Program Fee Percentage of hotel occupancy gross revenue paid for program fee. Additional borrowing capacity Line of Credit Facility, Allowable Additional Borrowing Capacity Line of Credit Facility, Allowable Additional Borrowing Capacity Statistical Measurement [Axis] Statistical Measurement [Axis] Credit Facility [Axis] Credit Facility [Axis] Provision for uncollectable rental income Provision for Lease Losses Total Lessor, Operating Lease, Payments to be Received Industry Sector [Axis] Industry Sector [Axis] Lease rental income Lease rental income Lease rental income Senior Guaranteed Notes, Series F Senior Guaranteed Notes, Series F [Member] Senior Guaranteed Notes, Series F [Member] Forfeiture of restricted units Partners' Capital Account, Restricted Units Forfeiture Partners' Capital Account, Restricted Units Forfeiture Multifamily Multifamily Segment [Member] Multifamily Segment [Member] Deferred compensation Deferred Compensation Liability, Current and Noncurrent Entity Small Business Entity Small Business Basis of Presentation Consolidation, Policy [Policy Text Block] Derivative Instruments and Hedging Activities Disclosures [Table] Derivative Instruments and Hedging Activities Disclosures [Table] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Swap Swap [Member] Percentage rent Operating Lease, Variable Lease Income Eurodollar rate Debt Instrument, Variable Rate Basis, Three Debt Instrument, Variable Rate Basis, Three DEBT Debt Disclosure [Text Block] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Proceeds from issuance of common stock, net Proceeds from Issuance of Common Stock Amendment Flag Amendment Flag Computation of basic and diluted EPS Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Unsecured line of credit, net Long-term Line of Credit Distributions per unit (in USD per share) Distributions Per Limited Partnership and General Partnership Unit, Outstanding, Basic Fair Value Measurement Fair Value Measurement, Policy [Policy Text Block] Reclassification of amortization of forward-starting swap realized gains included in interest expense Reclassification of amortization of forward-starting swap realized gains included in interest expense Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Forfeiture of restricted stock (shares) Stock Issued During Period, Shares, Restricted Stock Award, Forfeited Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities COMPREHENSIVE INCOME Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Entity Central Index Key Entity Central Index Key Related Party [Domain] Related Party [Domain] Measurement Frequency [Axis] Measurement Frequency [Axis] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Plus: Income from operations attributable to unitholders in the Operating Partnership-diluted Minority Interest In Continuing Operations Income Loss Operating Partnerships - Diluted Minority Interest In Continuing Operations Income Loss Operating Partnerships - Diluted Derivative Instrument [Axis] Derivative Instrument [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Capital expenditures Payments for Capital Improvements Fair Value Measurement [Domain] Fair Value Measurement [Domain] Unsecured senior guaranteed notes, net Senior Notes [Member] Repairs and maintenance Cost of Property Repairs and Maintenance SUBSEQUENT EVENT Subsequent Events [Text Block] Maximum proportion of total revenue provided by any single tenant (as a percent) Maximum Percentage Of Revenue Provided By Any Single Tenant Maximum percentage of revenue provided by any single tenant. Leasing commissions, accumulative amortization Deferred Costs, Leasing, Accumulated Amortization Effective Date Derivative, Inception Date Maximum proportion of hotel's fiscal year gross revenues paid for aggregate yearly management fee (as a percent) Maximum Percentage Of Hotels Fiscal Year Gross Revenues Paid For Aggregate Yearly Management Fee Maximum percentage of hotels fiscal year gross revenues paid for aggregate yearly Management fee. Dividends period Dividends Quarterly Period Dividends quarterly period. Segments [Domain] Segments [Domain] Repayments of Unsecured Debt Repayments of Unsecured Debt Repayments of Unsecured Debt Lease extension option exercise period Lessee, Operating Lease, Renewal Term Maximum recourse indebtedness of total asset value Maximum Recourse Indebtedness of Total Asset Value Maximum Recourse Indebtedness of Total Asset Value Rental Income [Line Items] Rental Income [Line Items] Rental Income [Line Items] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Del Monte Center Del Monte Center Affiliates [Member] Del Monte Center Affiliates. Proceeds from Debt, Net of Issuance Costs Proceeds from Debt, Net of Issuance Costs Below market leases Below Market Lease, Gross Activity of restricted stock awards Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Income Statement Location [Axis] Income Statement Location [Axis] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Number of consolidated properties located in Southern California Number Of Consolidated Properties Number of consolidated properties. Income Statement Location [Domain] Income Statement Location [Domain] Senior Guaranteed Notes, Series G Senior Guaranteed Notes, Series G [Member] Senior Guaranteed Notes, Series G 2023 Lessee, Operating Lease, Liability, to be Paid, Year Two FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities [Abstract] Term Loan B Term Loan B [Member] Term Loan B [Member] Notional Amount Derivative, Notional Amount Office Office Segment [Member] Office Segment. Lease costs under operating leases and supplemental cash flow information of leases Lease, Cost [Table Text Block] Previous months of management fees Previous Months Of Management Fees The previous months management fees used in the calculation of the management cancellation fee. Interest and investment income Interest and Other Income 2024 Lessee, Operating Lease, Liability, to be Paid, Year Three Hotel management agreement default penalty factor of previous twelve months of management fees in fifteenth year of term Hotel Management Agreement Default Penalty Factor Of Previous Twelve Months Of Management Fees In Fifteenth Year Of Term Hotel management agreement default penalty factor of previous twelve months of Management fees in fifteenth year of term. Other liabilities Other Liabilities Acquired lease intangible liabilities, net Below Market Lease, Net Room in mixed-use segment all-suite hotel Number Of Rooms In Mixed Use Segment All Suite Hotel Number of rooms in mixed use segment all suite hotel. SEGMENT REPORTING Segment Reporting Disclosure [Text Block] Lease extension options exercise period Lease Extension Options Exercise Period The period which lease extension options can be exercisable. Income from operations attributable to American Assets Trust, Inc. common stockholders—basic Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Total assets Assets RELATED PARTY TRANSACTIONS Related Party Transactions Disclosure [Text Block] Deferred Rent Repayments - COVID-19 Deferred Rent Repayments - COVID-19 Deferred Rent Repayments - COVID-19 Net income attributable to restricted shares Less: Net income attributable to restricted shares Net Income Attributable To Restricted Share Net income attributable to restricted share. Nonvested, Beginning, Shares Nonvested, End of year, shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Title of 12(b) Security Title of 12(b) Security Acquired lease intangible assets, net Finite-Lived Intangible Assets, Net Subsequent Event Type [Axis] Subsequent Event Type [Axis] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Lessor, Lease, Description [Table] Lessor, Lease, Description [Table] Number of sales agents Number of Sales Agents Number of Sales Agents LEASES Lessor, Operating Leases [Text Block] Property management fee (as a percent) Property Management Fee, Percent Fee 2023 Lessor, Operating Lease, Payment to be Received, Year Two Interest expense Interest expense Interest expense Interest Expense Future Year Period Four Future Year Period Four [Member] Future year period four. Debt Securities, Held-to-Maturity, Weighted Average Yield, Maturity, after Year 10 Debt Securities, Held-to-Maturity, Weighted Average Yield, Maturity, after Year 10 Depreciation and amortization Depreciation, Depletion and Amortization Percentage of ownership interests classified as noncontrolling Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Property Expenses Property Expenses Property expenses. City Center Bellevue City Center Bellevue [Member] City center bellevue. Marketing Marketing Expense Total liabilities Liabilities Wells Fargo Bank, N.A. Wells Fargo Bank, N.A. [Member] Wells Fargo Bank, N.A. [Member] Partner Capital Components [Axis] Partner Capital Components [Axis] Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Retail Retail Segment [Member] Retail Segment. Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Net income attributable to American Assets Trust, Inc. stockholders Net Income (Loss) Available to Common Stockholders, Basic Fair Value, Inputs, Level 1 Fair Value, Inputs, Level 1 [Member] Rent Operating Lease, Expense Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Amount per Share/Unit (in USD per unit) Common Stock, Dividends, Per Share, Cash Paid Purchase Commitment, Excluding Long-term Commitment [Domain] Purchase Commitment, Excluding Long-term Commitment [Domain] Additional Paid-in Capital Additional Paid-in Capital [Member] Debt Instrument [Axis] Debt Instrument [Axis] Principal components of other expense, net Schedule of Other Nonoperating Income (Expense) [Table Text Block] Debt issuance costs, accumulated amortization Debt issuance costs, accumulated amortization Accumulated Amortization, Debt Issuance Costs Partner Type [Axis] Partner Type [Axis] Other assets, net Total other assets Other Assets Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] General partners' capital, units issued (in shares) General Partners' Capital Account, Units Issued Interest rate swap liability Derivative Liability Total capital Beginning partners' capital account Ending partners' capital account Partners' Capital Term Loan C Term Loan C [Member] Term Loan C [Member] Common stock, shares outstanding (shares) Beginning Balance (shares) Ending Balance (shares) Common Stock, Shares, Outstanding Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Variable lease cost Variable Lease, Cost Effect of dilutive securities-conversion of Operating Partnership units (in shares) Incremental Common Shares Attributable To Conversion Of Operating Partnership Units Incremental common shares attributable to conversion of Operating partnership units. Other property income Other Operating Income 3.375% Senior Unsecured Notes 3.375% Senior Unsecured Notes [Member] 3.375% Senior Unsecured Notes EXPENSES: Operating Costs and Expenses [Abstract] Revolving Credit Facility Revolving Credit Facility [Member] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Derivative contract term Derivative, Term of Contract Subsequent Event Subsequent Event [Member] Amount recovered for reimbursements of operating expense for related party Amount Recovered For Reimbursements Of Operating Expense For Related Party Amount recovered for reimbursements of operating expense for related party. PARTNERS' CAPITAL OF AMERICAN ASSETS TRUST, L.P. Partners' Capital Notes Disclosure [Text Block] Common stock, shares authorized (in shares) Common Stock, Shares Authorized Concentration Risk Type [Axis] Concentration Risk Type [Axis] Limited partners' capital, 16,181,537 and 16,181,537 units issued and outstanding as of June 30, 2021 and December 31, 2020, respectively Limited Partners' Capital Account Capital Unit [Line Items] Capital Unit [Line Items] Mixed-use Mixed Use Segment [Member] Mixed Use Segment [Member] Prepaid expenses and other Prepaid Expense Fair Value Estimate of Fair Value Measurement [Member] Income Statement [Abstract] Income Statement [Abstract] Future Year Period Two Future Year Period Two [Member] Future year period two. Remaining capacity to issue Remaining Capacity To Issue Remaining $ Capacity Of Shares To Issue Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Maximum secured leverage ratio on revolving credit facility Maximum Secured Leverage Ratio On Revolving Credit Facility Maximum Secured Leverage Ratio On Revolving Credit Facility Equity [Table] Equity [Table] Equity [Table] Term Loan A Term Loan A [Member] Term Loan A [Member] Senior Guaranteed Notes, Series C Senior Guaranteed Notes, Series C [Member] Senior Guaranteed Notes, Series C [Member] Eastgate Office Park [Member] Eastgate Office Park [Member] Eastgate Office Park Term Loan B & Term Loan C Term Loan B & Term Loan C [Member] Term Loan B & Term Loan C [Member] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Recognition of amortization of above and below market leases Amortization of above and below Market Leases Schedule of acquired lease intangibles included in other assets and other liabilities Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Future Year Period One Future Year Period One [Member] Future year period one. Dividends declared and paid Dividends Comprehensive income attributable to American Assets Trust, Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Extension term Debt Instrument, Extension Term Debt Instrument, Extension Term Senior Unsecured Notes Senior Unsecured Notes [Member] Senior Unsecured Notes Counterparty Name [Domain] Counterparty Name [Domain] City Area Code City Area Code Legal Entity [Axis] Legal Entity [Axis] Operating cash flow information: Cash Flow, Operating Activities, Lessee [Abstract] Future Time Period Prior to 12-31-2021 Future Time Period Prior [Member] Future time period prior. Document Period End Date Document Period End Date Senior Guaranteed Notes, Series B Senior Guaranteed Notes, Series B [Member] Senior Guaranteed Notes, Series B Distributions Partners' Capital Account, Distributions Security deposits payable Security Deposit Liability OTHER LIABILITIES AND DEFERRED CREDITS Other Liabilities Disclosure [Text Block] NET INCOME Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Waikiki Beach Walk - Retail Waikiki Beach Walk Retail [Member] Waikiki Beach walk retail. Basis spread on federal funds rate Debt Instrument, Spread on Variable Rate Basis, Two Debt Instrument, Spread on Variable Rate Basis, Two Hedging Designation [Axis] Hedging Designation [Axis] Real estate taxes Real Estate Tax Expense Proceeds from unsecured notes payable Proceeds from Issuance of Senior Long-term Debt Dividends declared and paid on shares of common stock and noncontrolling common units Dividends Declared And Paid On Shares Of Common Stock And Noncontrolling Common Units Table [Table Text Block] Dividends declared and paid on shares of common stock and noncontrolling common units. Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Stock-based compensation expense Share-based Payment Arrangement, Noncash Expense Payments to Acquire Productive Assets Payments to Acquire Productive Assets Senior Guaranteed Notes, Series A Senior Guaranteed Notes, Series A [Member] aat_SeniorGuaranteedNotes,SeriesA Entity [Domain] Entity [Domain] Designated as Hedging Instrument Designated as Hedging Instrument [Member] Issuance of restricted stock (shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Unsecured notes payable, net Unsecured Debt Cover page. Cover [Abstract] Base Rate Base Rate [Member] Loss on derivative settlement Derivative, Loss on Derivative Debt extension options Debt Instrument, Extension Options Debt Instrument, Extension Options ACQUIRED IN-PLACE LEASES AND ABOVE/BELOW MARKET LEASES Intangible Assets Disclosure [Text Block] Net real estate and secured note payable balances by segments Net Real Estate And Secured Note Payable Balances By Segment Table [Table Text Block] Tabular disclosure of the net real estate and secured note payable balances by segment. Total Debt Outstanding Long-term Debt LEASES Lessee, Operating Leases [Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] In-place leases Leases, Acquired-in-Place [Member] Restricted cash Restricted Cash and Cash Equivalents OTHER (EXPENSE) INCOME, NET Other Income and Other Expense Disclosure [Text Block] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Leases, gross Acquired above market leases, net Finite-Lived Intangible Asset, Off-market Lease, Favorable, Gross Total operating expenses Costs and Expenses Equity Components [Axis] Equity Components [Axis] Partner Capital Components [Domain] Partner Capital Components [Domain] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Minimum Minimum [Member] Business and Organization Business And Organization, Policy [Policy Text Block] Business and organization. Aggregate offering price of common share Aggregate Offering Price Of Common Share Maximum aggregate offering price of common shares. Unrecognized compensation expense Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount Early Extinguishment of Debt Early Extinguishment of Debt [Member] Early Extinguishment of Debt Industry Sector [Domain] Industry Sector [Domain] Consolidated Statements of Cash Flows-Supplemental Disclosures Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Years of contract Years Of Contract Years of contract. Hotel operating Other Cost of Operating Revenue Financial liabilities measured at fair value on recurring basis Fair Value, Liabilities Measured on Recurring Basis [Table Text Block] Forfeited, Weighted Average Grant Date Fair Value (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value American Assets Trust, L.P. American Assets Trust, L.P. [Member] American Assets Trust, L.P. [Member] Noncash compensation expense Restricted Stock or Unit Expense Entity Interactive Data Current Entity Interactive Data Current Increase (Decrease) in Partners' Capital [Roll Forward] Increase (Decrease) in Partners' Capital [Roll Forward] REVENUE: Revenues [Abstract] FAIR VALUE OF FINANCIAL INSTRUMENTS Fair Value Disclosures [Text Block] OPERATING ACTIVITIES Net Cash Provided by (Used in) Operating Activities [Abstract] Termination payment Loss on Contract Termination for Default Leasing commissions, net of accumulated amortization of $38,227 and $35,167, respectively Deferred Costs, Leasing, Net Interest Rate Swap Interest Rate Swap [Member] Net income attributable to unitholders in the Operating Partnership Net income attributable to unitholders in the Operating Partnership Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable Acquired in-place leases, net Finite-Lived Intangible Asset, Acquired-in-Place Leases Additional paid-in capital Additional Paid in Capital, Common Stock Entity Registrant Name Entity Registrant Name Subsequent Event Type [Domain] Subsequent Event Type [Domain] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Weighted-average discount rate - operating leases (as a percent) Operating Lease, Weighted Average Discount Rate, Percent Total Real estate, at cost Real Estate Investment Property, at Cost Management fees Management Fee Expense Years, maximum term range of office and retail leases Years Maximum Term Range Of Office And Retail Leases Years maximum term range of office and retail leases. Schedule of segments operating activity Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Debt issuance costs, net of accumulated amortization of $1,425 and $0, respectively Debt issuance costs, net Debt Issuance Costs, Net Allowance for Doubtful Accounts, Rent Receivables Allowance for Doubtful Accounts, Premiums and Other Receivables Estimated derivative reclassification from Accumulated OCI to Income Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Effective rate of debt instrument (in percent) Debt Instrument, Interest Rate, Effective Percentage Hotel management agreement default penalty factor of previous twelve months of management fees in first 11 years of term Hotel Management Agreement Default Penalty Fact Or Of Previous Twelve Months Of Management Fees In First Eleven Years Of Term Hotel management agreement default penalty fact or of previous twelve months of Management fees in first eleven years of term. Forward Contracts Forward Contracts [Member] At The Market Equity Program At The Market Equity Program [Member] At The Market Equity Program [Member] Operating Partnership Units Operating Partnership Units [Member] Operating Partnership Units [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Real Estate [Domain] Real Estate [Domain] Deferred rent receivables, net Deferred Rent Receivables, Net Total lease payments Lessee, Operating Lease, Liability, to be Paid Minimum base rate Debt Instrument, Variable Rate Basis, Four. Debt Instrument, Variable Rate Basis, Four. Depreciation and amortization Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Years, minimum term range of office and retail leases Years Minimum Term Range Of Office And Retail Leases Years minimum term range of office and retail leases. Stock-based compensation Partners' Capital Account, Unit-based Payment Arrangement, Amount Rental income Total rental income Operating Lease, Lease Income Recognition of straight-line rents Straight Line Rent Line Of Credit Future Time Period [Axis] Line Of Credit Future Time Period [Axis] Line Of Credit Future Time Period [Axis] Sale of Stock [Axis] Sale of Stock [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Date dividend to be paid Dividends Payable, Date to be Paid Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Carrying amount and fair value of financial instruments Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Document Transition Report Document Transition Report Senior Guaranteed Notes, Series E Senior Guaranteed Notes, Series E [Member] Senior Guaranteed Notes, Series E [Member] General Partner General Partner [Member] Straight-line rent liability Deferred Rent Credits Deferred Rent Credits Minimum unsecured leverage ratio Minimum Unsecured Interest Coverage Ratio Minimum Unsecured Interest Coverage Ratio COMPONENTS OF RENTAL INCOME AND EXPENSE Components Of Rental Income And Expense [Text Block] The entire disclosure of the principle components of rental income and/or rental expense recognized for the period. Dividends declared per common share (in USD per share) Common Stock, Dividends, Per Share, Declared Face amount of debt Debt Instrument, Face Amount Debt issuance costs, net, revolving credit facility Debt Issuance Costs, Line of Credit Arrangements, Net Fair Value, Inputs, Level 2 Fair Value, Inputs, Level 2 [Member] Change in other liabilities and deferred credits Increase (Decrease) in Other Deferred Liability American Assets, Inc. American Assets, Inc. [Member] American Assets, Inc. [Member] Proportion of hotel occupancy gross revenue paid for franchise royalty fee (as a percent) Percentage Of Hotel Occupancy Gross Revenue Paid For Franchise Royalty Fee Percentage of hotel occupancy gross revenue paid for franchise royalty fee. Document Quarterly Report Document Quarterly Report Months, maximum term of apartment leases Months Maximum Term Length Of Apartment Leases Months maximum term length of apartment leases. Proceeds from unsecured line of credit Proceeds from Unsecured Lines of Credit Equity [Abstract] Equity [Abstract] Derivative fixed interest rate (in percent) Derivative, Fixed Interest Rate Leasing commissions Increase (Decrease) in Lease Acquisition Costs Subsequent Event [Line Items] Subsequent Event [Line Items] Credit Facility [Domain] Credit Facility [Domain] Weighted average shares of common stock outstanding-diluted (in shares) Weighted average common shares outstanding - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Derivative Contract [Domain] Derivative Contract [Domain] Earnings per common share, basic (in USD per share) Earnings Per Share, Basic Lease incentives, net of accumulated amortization of $896 and $802, respectively Incentive to Lessee Other Income and Expenses [Abstract] Other Income and Expenses [Abstract] Number of operating segments Number of Operating Segments Entity File Number Entity File Number Forfeited, Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Debt Disclosure [Abstract] Debt Disclosure [Abstract] Weighted-average remaining lease term - operating leases (in years) Operating Lease, Weighted Average Remaining Lease Term Principal components of rental income Components Of Rental Income Table [Table Text Block] Components of rental income. Amortization of debt issuance costs and debt discounts Amortization of Debt Issuance Costs and Discounts 2025 Lessor, Operating Lease, Payment to be Received, Year Four Unsecured term loans, net Unsecured Debt [Member] Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Future Year Period Three Future Year Period Three [Member] Future year period three. Revenue from Contract with Customer, Including Assessed Tax Revenue from Contract with Customer, Including Assessed Tax Counterparty Name [Axis] Counterparty Name [Axis] Common stock, $0.01 par value, 490,000,000 shares authorized, 60,474,866 and 60,476,292 shares issued and outstanding at June 30, 2021 and December 31, 2020, respectively Common Stock, Value, Issued Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Document Fiscal Year Focus Document Fiscal Year Focus Entity Current Reporting Status Entity Current Reporting Status Federal Funds Rate Federal Funds Rate [Member] Interest based on Federal Funds Rate. Other Liabilities Disclosure [Abstract] Other Liabilities Disclosure [Abstract] Subsequent Event [Table] Subsequent Event [Table] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Granted, Weighted Average Grant Date Fair Value (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities [Abstract] Common stock, shares issued (in shares) Common Stock, Shares, Issued Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Eurodollar Eurodollar [Member] Maximum leverage ratio of revolving credit facility Line Of Credit Facility Maximum Leverage Percentage Maximum leverage percentage of revolving credit facility. Investment in WBW CHP LLC (as a percent) Percentage Of Investment In Related Party Percentage of investment in related party. AAI Aviation, Inc. AAI Aviation, Inc. [Member] AAI Aviation Inc [Member] Industry Concentration Risk Industry Concentration Risk [Member] Industry Concentration Risk Lease liability Present value of lease liability Operating Lease, Liability Years in hotel management agreement term Years In Hotel Management Agreement Term Years in hotel management agreement term. Deferred tax liability Deferred Tax Liabilities, Net Rental operating Direct Costs Of Leased Property, Lessor, Expense Direct Costs Of Leased Property, Lessor, Expense Segment Reporting [Abstract] Segment Reporting [Abstract] Accounts receivable, net Accounts Receivable, after Allowance for Credit Loss Purchase Commitment, Excluding Long-term Commitment [Axis] Purchase Commitment, Excluding Long-term Commitment [Axis] Interest Expense Interest Expense [Member] Change in accounts receivable Increase (Decrease) in Accounts Receivable Debt Instrument [Line Items] Debt Instrument [Line Items] Total American Assets Trust, Inc. stockholders’ equity Stockholders' Equity Attributable to Parent Concentration Risk Type [Domain] Concentration Risk Type [Domain] TOTAL LIABILITIES AND EQUITY Liabilities and Equity Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax INCOME TAXES Income Tax Disclosure [Text Block] Entity Address, City or Town Entity Address, City or Town Secured Notes Payable Notes Payable Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Non-cash activity: Non-Cash Activity [Abstract] Non-Cash Activity [Abstract] Basis spread on Eurodollar rate Debt Instrument, Spread on Variable Rate Basis, Three Debt Instrument, Spread on Variable Rate Basis, Three Schedule of Interest Rate Derivatives Schedule of Interest Rate Derivatives [Table Text Block] Operating lease cost Operating Lease, Cost Second Amended and Restated Credit Facility Second Amended and Restated Credit Facility [Member] Second Amended and Restated Credit Facility [Member] Hedging Relationship [Axis] Hedging Relationship [Axis] General and administrative General and administrative General and Administrative Expense Acquired below market leases, net Off-market Lease, Unfavorable Minimum fixed charge coverage ratio covenant threshold Minimum Fixed Charge Coverage Ratio On Revolving Credit Facility Minimum Fixed Charge Coverage Ratio On Revolving Credit Facility Antidilutive securities excluded from computation of EPS (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Other, net Other Noncash Income (Expense) Equity Component [Domain] Equity Component [Domain] Dividends paid to common stock and unitholders Payments of Dividends Total segments’ profit Gross Profit Hotel management agreement default penalty factor of previous twelve months of management fees in fourteenth year of term Hotel Management Agreement Default Penalty Fact Or Of Previous Twelve Months Of Management Fees In Fourteenth Year Of Term Hotel management agreement default penalty fact or of previous twelve months of Management fees in fourteenth year of term. Entity Tax Identification Number Entity Tax Identification Number Maximum unsecured leverage ratio Maximum Unsecured Leverage Ratio Maximum Unsecured Leverage Ratio Years, environmental remediation length Years Environmental Remediation Length Years environmental remediation length. Deferred Rent Repayments - COVID-19 (Percentage) Deferred Rent Repayments - COVID-19 (Percentage) Deferred Rent Repayments - COVID-19 (Percentage) Changes in operating assets and liabilities Increase (Decrease) in Operating Capital [Abstract] Rental Income [Table] Rental Income [Table] Rental Income [Table] 2021 (six months ending December 31, 2021) Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year London Interbank Offered Rate (LIBOR) London Interbank Offered Rate (LIBOR) [Member] Leases [Abstract] Leases [Abstract] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Current Fiscal Year End Date Current Fiscal Year End Date Comprehensive income attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Interest rate swap liability Interest rate swap liability Interest Rate Derivative Liabilities, at Fair Value Interest Rate Derivative Liabilities, at Fair Value Reconciliation of segment profit to net income attributable to stockholders Reconciliation Of Segment Profit To Net Income Attributable To Stockholders Table [Table Text Block] Reconciliation of segment profit to net income attributable to stockholders. Above market leases Above Market Leases [Member] Other non-operating income Other Nonoperating Income American Assets Trust, Inc. stockholders’ equity Stockholders' Equity Attributable to Parent [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Capital expenditures for each segment Cash Flow, Operating Capital [Table Text Block] Number of employees Entity Number of Employees Office, retail, multifamily, and mixed-use operating properties Number of Real Estate Properties Revenue Recognition and Deferred Revenue [Abstract] Net income attributable to common stockholders-diluted Net Income (Loss) Available to Common Stockholders, Diluted U.S. Bank N.A. U.S. Bank N.A. [Member] U.S. Bank N.A. [Member] Change in security deposits payable Increase (Decrease) in Security Deposits Payable Increase (Decrease) in Security Deposits Payable Lease incentives, accumulated amortization Lease Incentive Accumulated Amortization Lease Incentive Accumulated Amortization Term of contract (in years) Lessor, Operating Lease, Term of Contract Interest Rate Swap, 3/1/2023 Interest Rate Swap, 3/1/2023 [Member] Interest Rate Swap, 3/1/2023 [Member] Entity Filer Category Entity Filer Category Common Shares Common Stock [Member] Land Mark At One Market [Member] Land Mark At One Market [Member] Land mark at one market. Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Principal components of rental expenses Components Of Rental Expense Table [Table Text Block] Components of rental expense. Other intangible assets, net of accumulated amortization of $1,349 and $1,213, respectively Other Finite-Lived Intangible Assets, Gross Fair value assumptions, interest rate (as a percent) Debt Instrument, Measurement Input Accumulated accretion Below Market Lease, Accumulated Amortization 2022 Lessor, Operating Lease, Payment to be Received, Year One Secured notes payable, net Secured Debt [Member] Lessor, Lease, Description [Line Items] Lessor, Lease, Description [Line Items] Stated Interest Rate Debt Instrument, Interest Rate, Stated Percentage EARNINGS PER COMMON SHARE, DILUTED Earnings Per Share, Diluted [Abstract] Limited partners' capital, units outstanding (in shares) Limited Partners' Capital Account, Units Outstanding Related Party Transactions [Abstract] Related Party Transactions [Abstract] Net increase in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Hedging Relationship [Domain] Hedging Relationship [Domain] Operating real estate Rental Properties Current minimum annual payments under the leases Lessee, Operating Lease, Liability, Maturity [Table Text Block] Significant Accounting Policies Basis of Accounting, Policy [Policy Text Block] Accounts payable and accrued liabilities for construction in progress Increase (Decrease) Accrued Construction in Progress Change in accrued liabilities for construction in progress. Weighted average shares of common stock outstanding-basic (in shares) Weighted average common shares outstanding-basic (in shares) Weighted Average Number of Shares Outstanding, Basic Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Deferred rent expense and lease intangible Deferred Rent Expense And Lease Intangible Deferred rent expense and lease intangible. Subsequent Events [Abstract] Ownership [Axis] Ownership [Axis] Document Information [Line Items] Document Information [Line Items] Other liabilities and deferred credits Other Liabilities And Deferred Credits Table [Table Text Block] Tabular disclosure of other liabilities and deferred credits not separately disclosed on the balance sheet. Operating leases rental period terms Operating Leases Rental Period Terms Operating Leases Rental Period Terms Hawaii excise tax Excise and Sales Taxes Sale of Stock [Domain] Sale of Stock [Domain] Cash Flow Hedging Cash Flow Hedging [Member] Ownership [Domain] Ownership [Domain] Weighted average interest rate, revolving credit facility Line of Credit Facility, Interest Rate During Period Carrying Value Reported Value Measurement [Member] Cash paid for interest, net of amounts capitalized Interest Paid, Excluding Capitalized Interest, Operating Activities Total equity Beginning Balance Ending Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Right-of-use assets obtained in exchange for operating lease obligations Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] WBW CHP LLC WBW CHP LLC [Member] WBW CHP LLC Revenue Recognition, Leases Revenue Recognition, Leases [Policy Text Block] EQUITY OF AMERICAN ASSETS TRUST, INC. Shareholders' Equity and Share-based Payments [Text Block] Long-term debt, fair value Long-term Debt, Fair Value Total revenue Revenues Income tax benefit (expense) Income tax (benefit) expense Income Tax Expense (Benefit) Cash, cash equivalents and restricted cash, beginning of period Cash, cash equivalents and restricted cash, end of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Federal funds rate Debt Instrument, Variable Rate Basis, Two Debt Instrument, Variable Rate Basis, Two Maturity Date Derivative, Maturity Date Purchases of marketable securities Payments to Acquire Marketable Securities Stated Maturity Date Debt Instrument, Maturity Date Deferred compensation liability Financial and Nonfinancial Liabilities, Fair Value Disclosure Other noncash interest expense Other Non-cash Interest Expense Other Non-cash Interest Expense Earnings per common share, diluted (in USD per share) Earnings Per Share, Diluted Local Phone Number Local Phone Number Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Summary of total secured notes payable outstanding Schedule of Debt [Table Text Block] Deferred rent revenue and amortization of lease intangibles Deferred Rent Revenue And Amortization Of Lease Intangibles The increase (decrease) during the reporting period in the amount due that is the result of the cumulative difference between actual rent due and rental income recognized on a straight-line basis. Also includes the amortization of lease intangibles. Long-term Debt, Principal Balance Long-term Debt, Gross Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Change in other assets Increase (Decrease) in Other Operating Assets Entity Emerging Growth Company Entity Emerging Growth Company Outrigger Hotels Outrigger Hotels And Resorts [Member] Outrigger hotels and resorts. Noncontrolling common units (in shares) Shares Held By Minority Interest In Operating Partnerships Shares held by minority interest in Operating partnerships. Note Offering Percent Note Offering Percent Note offering percent of principal amount Revolving credit facility borrowing limit, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Award Type [Axis] Award Type [Axis] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Accumulated amortization Other intangible assets, accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Repayment of secured notes payable Repayments of Secured Debt Maximum Maximum [Member] Prime rate Debt Instrument, Variable Rate Basis, One Debt Instrument, Variable Rate Basis, One Limited partners' capital, units issued (in shares) Limited Partners' Capital Account, Units Issued Noncontrolling Interests - Unitholders in the Operating Partnership Noncontrolling Interest [Member] Capital expenditures Capital Expenditures and Leasing Commissions Capital Expenditures and Leasing Commissions Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities Accumulated Dividends in Excess of Net Income Retained Earnings [Member] Measurement Basis [Axis] Measurement Basis [Axis] Common unit conversion ratio Partners Capital Redemption & Conversion Ratio Partners Capital Redemption & Conversion Ratio Thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Four Lessee, Operating Lease, Liability, to be Paid, after Year Four Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities 2024 Lessor, Operating Lease, Payment to be Received, Year Three Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Current minimum future rentals under the leases Lessor, Operating Lease, Payment to be Received, Fiscal Year Maturity [Table Text Block] Award Type [Domain] Award Type [Domain] Components of Other Assets Schedule of Other Assets [Table Text Block] Trading Symbol Trading Symbol Properties held for development Real Estate Properties Held For Development The number of real estate properties held for development. Months, minimum term of apartment leases Months Minimum Term Of Apartment Leases Months minimum term of apartment leases. General partner's capital, 60,474,866 and 60,476,292 units issued and outstanding as of June 30, 2021 and December 31, 2020, respectively General Partners' Capital Account Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Accumulated depreciation Real Estate Investment Property, Accumulated Depreciation Entity Shell Company Entity Shell Company Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Fair Value, Measurements, Recurring Fair Value, Recurring [Member] Fair Value Inputs Disclosures Fair Value Measurement Inputs and Valuation Techniques [Line Items] Segment Information Segment Reporting, Policy [Policy Text Block] Real estate, net Net Real Estate Real Estate Investment Property, Net Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] EARNINGS PER COMMON SHARE Earnings Per Share, Basic [Abstract]