Equity method investment summarized financial information debt.

No definition available.

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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.

+ References

No definition available.

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INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Investment in Real Estate Ventures and Share of Real Estate Ventures' Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 21, 2020	Aug. 01, 2018	Jun. 26, 2018	May 29, 2015	Jul. 31, 2013
Schedule of Equity Method Investments [Line Items]
Carrying Amount	$ 389,811	$ 120,294
Company's Share of Real Estate Venture Income (Loss)	(18,584)	(9,922)	$ (15,231)
Real Estate Venture Debt at 100%, gross	$ 963,018	596,007
Commerce Square Venture
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70.00%
Carrying Amount	$ 253,128	0
Company's Share of Real Estate Venture Income (Loss)	(9,150)	0
Real Estate Venture Debt at 100%, gross	$ 219,168	0
Mid-Atlantic Office JV
Schedule of Equity Method Investments [Line Items]
Ownership percentage	40.00%			40.00%
Carrying Amount	$ 32,996	0
Company's Share of Real Estate Venture Income (Loss)	96	0
Real Estate Venture Debt at 100%, gross	$ 120,831	0
Brandywine - AI Venture LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%
Carrying Amount	$ 10,302	10,116
Company's Share of Real Estate Venture Income (Loss)	185	(2,800)
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	$ 16,019	16,446
Company's Share of Real Estate Venture Income (Loss)	(358)	(498)
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	$ (11,516)	(70)
Company's Share of Real Estate Venture Income (Loss)	(6,570)	(6,102)
Real Estate Venture Debt at 100%, gross	$ 185,000	185,000			$ 180,800
PJP VII
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%
Carrying Amount	$ 0	0
Company's Share of Real Estate Venture Income (Loss)	0	190
Real Estate Venture Debt at 100%, gross	$ 0	0
PJP Two
Schedule of Equity Method Investments [Line Items]
Ownership percentage	30.00%
Carrying Amount	$ 0	0
Company's Share of Real Estate Venture Income (Loss)	0	81
Real Estate Venture Debt at 100%, gross	$ 0	0
PJP VI
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%
Carrying Amount	$ 0	0
Company's Share of Real Estate Venture Income (Loss)	0	(185)
Real Estate Venture Debt at 100%, gross	$ 0	0
1919 Ventures
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%					50.00%
Carrying Amount	$ 15,434	17,524
Company's Share of Real Estate Venture Income (Loss)	59	328
Real Estate Venture Debt at 100%, gross	$ 88,860	88,860
4040 Wilson Venture
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%							50.00%
Carrying Amount	$ 34,454	37,002
Company's Share of Real Estate Venture Income (Loss)	(2,162)	(368)
Real Estate Venture Debt at 100%, gross	$ 141,857	114,845
JBG 51 N 50 Patterson
Schedule of Equity Method Investments [Line Items]
Ownership percentage	70.00%						70.00%
Carrying Amount	$ 21,237	21,531
Company's Share of Real Estate Venture Income (Loss)	(457)	(313)
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%						70.00%
Carrying Amount	$ 17,757	17,745
Company's Share of Real Estate Venture Income (Loss)	(227)	(255)
Real Estate Venture Debt at 100%, gross	$ 0	$ 0