Discontinued Operations - Schedule of Results of Operations Related to Discontinued Operations (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Other income (expense):
Real estate impairment loss			$ (42,000)
Loss from discontinued operations, net		$ (5,075)	(33,811)
1899 Pennsylvania Avenue [Member]
Revenues:
Rental revenue	[1]	13,967
Other income	[1]	276
Total revenues	[1]	14,243
Expenses:
Operating	[1]	5,853
Depreciation and amortization	[1]	690
Total expenses	[1]	6,543
Other income (expense):
Income (loss) before gain or loss on sale of real estate	[1]	7,700
(Loss) gain on sale of real estate	[1],[2]	(12,766)
Loss before income taxes	[1]	(5,066)
Income tax expense	[1]	(9)
Loss from discontinued operations, net	[1]	$ (5,075)
1899 Pennsylvania Avenue and Liberty Place [Member]
Revenues:
Rental revenue	[1]		24,969
Other income	[1]		457
Total revenues	[1]		25,426
Expenses:
Operating	[1]		10,134
Depreciation and amortization	[1]		8,243
Total expenses	[1]		18,377
Other income (expense):
Real estate impairment loss	[1]		(42,000)
Income (loss) before gain or loss on sale of real estate	[1]		(34,951)
(Loss) gain on sale of real estate	[1],[2]		1,140
Loss before income taxes	[1]		(33,811)
Loss from discontinued operations, net	[1]		$ (33,811)

[1] Represents revenues, expenses, net income, and cash flow information of 1899 Pennsylvania Avenue in the year ended December 31, 2020 and 1899 Pennsylvania Avenue and Liberty Place in the year ended December 31, 2019

[2] Represents the loss on sale of 1899 Pennsylvania Avenue in 2020 and gain on sale of Liberty Place in 2019.