Investment in Unconsolidated Joint Ventures (Narrative) (Details) $ in Thousands								3 Months Ended		6 Months Ended		59 Months Ended
	Jul. 07, 2023	Jun. 28, 2023	Jun. 27, 2023 USD ($)	Jun. 02, 2023	Apr. 21, 2023 ft² Year	Apr. 20, 2023 USD ($)	Jan. 31, 2023 USD ($) ft² a Vehicles Building	Jun. 30, 2023 USD ($) ft²	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) ft²	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) ft²	Jun. 05, 2023 USD ($) ft²	Jun. 04, 2023 USD ($)	Dec. 31, 2022 USD ($)
Schedule of Equity Method Investments [Line Items]
Interest and Other Income								$ 17,343	$ 1,195	$ 28,284	$ 2,423
Related party note receivable								$ 88,834		$ 88,834		$ 88,834			$ 78,576
3 Hudson Boulevard [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage								25.00%		25.00%		25.00%
Interest and Other Income												$ 23,200
Worldgate Drive | Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Ownership Percentage							50.00%
Payments to Acquire Interest in Joint Venture							$ 17,000
Net Rentable Area (in sf) | ft²							350,000
Number of buildings | Building							2
Number of parking space | Vehicles							1,200
Area of Land | a							10
7750 Wisconsin Avenue [Member] | Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Ownership Percentage					50.00%
Net Rentable Area (in sf) | ft²					734,000
Construction Loan						$ 252,600
Debt Instrument, Description of Variable Rate Basis				Term Secured Overnight Finance Rate (“SOFR”)	LIBOR	London interbank offered rate (“LIBOR”)
Extension Option (in years)					1	1
Number of extensions						2
7750 Wisconsin Avenue [Member] | Unconsolidated Properties | London Interbank Offered Rate (LIBOR)
Schedule of Equity Method Investments [Line Items]
Debt Instrument, Basis Spread on Variable Rate					1.25%	1.25%
7750 Wisconsin Avenue [Member] | Unconsolidated Properties | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Schedule of Equity Method Investments [Line Items]
Debt Instrument, Basis Spread on Variable Rate				1.35%
500 North Capitol Street, NW | Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Ownership Percentage													30.00%
Net Rentable Area (in sf) | ft²													231,000
Debt													$ 105,000	$ 105,000
Debt, Weighted Average Interest Rate													6.83%
500 North Capitol Street, NW | Unconsolidated Properties | Company's Share [Member]
Schedule of Equity Method Investments [Line Items]
Related party note receivable													$ 10,500
3 Hudson Boulevard [Member] | Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		25.00%
Debt Instrument, Description of Variable Rate Basis		LIBOR	LIBOR
Debt Instrument, Basis Spread on Variable Rate		3.50%	3.50%
Debt			$ 80,000
Number of extensions		1	2
Extension Option (in days)			30 days
Extension Option Two (in days)		180 days	180 days
3 Hudson Boulevard [Member] | Unconsolidated Properties | Subsequent Event [Member]
Schedule of Equity Method Investments [Line Items]
Debt Instrument, Description of Variable Rate Basis	Term SOFR
Debt Instrument, Basis Spread on Variable Rate	3.61%
3 Hudson Boulevard [Member] | Unconsolidated Properties | Extended Maturity
Schedule of Equity Method Investments [Line Items]
Debt Instrument, Term		30 days
Platform 16 | Unconsolidated Properties
Schedule of Equity Method Investments [Line Items]
Ownership Percentage								55.00%		55.00%		55.00%
Net Rentable Area (in sf) | ft²								390,000		390,000		390,000