Equity method investment summarized financial information debt.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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- Definition

Amount of income (loss) for proportionate share of equity method investee's income (loss).

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Schedule of Investment in Real Estate Ventures and Share of Real Estate Ventures' Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Nov. 30, 2022	Feb. 02, 2021	Dec. 21, 2020
Schedule of Equity Method Investments [Line Items]
Carrying Amount	$ 532,224	$ 411,110
Company's Share of unconsolidated real estate venture Income (Loss)	(22,016)	(26,697)	$ (18,584)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 1,204,779	961,509
Commerce Square Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	70.00%
Carrying Amount	$ 238,105	247,798
Company's Share of unconsolidated real estate venture Income (Loss)	(12,128)	(15,501)	(9,150)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 206,737	213,069
Mid-Atlantic Office Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	40.00%					40.00%
Carrying Amount	$ 31,005	31,680
Company's Share of unconsolidated real estate venture Income (Loss)	412	932	96
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 128,904	123,015
Brandywine - AI Venture LLC
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%
Carrying Amount	$ 0	0
Company's Share of unconsolidated real estate venture Income (Loss)	0	(721)	185
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
Herndon Innovation Center Metro Portfolio Venture, LLC
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	15.00%
Carrying Amount	$ 15,304	15,844
Company's Share of unconsolidated real estate venture Income (Loss)	(536)	(174)	(358)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 207,302	207,302
MAP Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%
Carrying Amount	$ (35,411)	(24,396)
Company's Share of unconsolidated real estate venture Income (Loss)	(8,340)	(8,683)	(6,570)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 182,053	184,263
Cira Square
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	20.00%
Carrying Amount	$ 27,815	0
Company's Share of unconsolidated real estate venture Income (Loss)	(985)	0	0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 257,700	0
4040 Wilson Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%
Carrying Amount	$ 29,633	31,059
Company's Share of unconsolidated real estate venture Income (Loss)	(1,211)	(2,258)	(2,162)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 145,070	145,000
1919 Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%			50.00%
Carrying Amount	$ 0	13,791
Company's Share of unconsolidated real estate venture Income (Loss)	1,392	427	59
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	88,860
3025 JFK Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	55.00%				55.00%
Carrying Amount	$ 57,630	56,370
Company's Share of unconsolidated real estate venture Income (Loss)	(35)	(118)	0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 60,118	0
JBG 51 N Street
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	70.00%
Carrying Amount	$ 21,208	21,213
Company's Share of unconsolidated real estate venture Income (Loss)	(382)	(402)	(457)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
JBG 1250 First Street Office
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	70.00%
Carrying Amount	$ 17,759	17,751
Company's Share of unconsolidated real estate venture Income (Loss)	(195)	(199)	(227)
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
3151 Market Street Venture
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	55.00%
Carrying Amount	$ 63,751	0
Company's Share of unconsolidated real estate venture Income (Loss)	(8)	0	0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	0
One Uptown - Office
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%
Carrying Amount	$ 34,980	0
Company's Share of unconsolidated real estate venture Income (Loss)	0	0	0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 16,895	0
One Uptown - Multifamily
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%
Carrying Amount	$ 30,445	0
Company's Share of unconsolidated real estate venture Income (Loss)	0	0	$ 0
Unconsolidated Real Estate Venture Debt at 100%, gross	$ 0	$ 0