SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION - Reconciliation of Carrying Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Initial Cost to Company
Land	$ 44,060
Buildings and Improvements	272,927
Costs Capitalized Subsequent to Acquisition, Net	101,152
Impairment/Write Downs	(12,037)
Cost Amount Carried at Close of Period
Land	44,060
Buildings and Improvements	362,042
Total	406,102
Accumulated Depreciation	156,439	$ 143,319	$ 202,700	$ 375,968
1225 Seventeenth Street
Initial Cost to Company
Land	22,400
Buildings and Improvements	110,090
Costs Capitalized Subsequent to Acquisition, Net	46,692
Impairment/Write Downs	(3,349)
Cost Amount Carried at Close of Period
Land	22,400
Buildings and Improvements	153,433
Total	175,833
Accumulated Depreciation	52,749
1250 H Street, NW
Initial Cost to Company
Land	5,975
Buildings and Improvements	53,778
Costs Capitalized Subsequent to Acquisition, Net	19,333
Impairment/Write Downs	(3,537)
Cost Amount Carried at Close of Period
Land	5,975
Buildings and Improvements	69,574
Total	75,549
Accumulated Depreciation	38,762
206 East 9th Street
Initial Cost to Company
Land	7,900
Buildings and Improvements	38,533
Costs Capitalized Subsequent to Acquisition, Net	6,967
Impairment/Write Downs	(1,501)
Cost Amount Carried at Close of Period
Land	7,900
Buildings and Improvements	43,999
Total	51,899
Accumulated Depreciation	11,073
Bridgepoint Square
Initial Cost to Company
Land	7,785
Buildings and Improvements	70,526
Costs Capitalized Subsequent to Acquisition, Net	28,160
Impairment/Write Downs	(3,650)
Cost Amount Carried at Close of Period
Land	7,785
Buildings and Improvements	95,036
Total	102,821
Accumulated Depreciation	$ 53,855