Summary of Significant Accounting Policies - Components of Revenue Streams, Timing of Satisfying Performance Obligations, and Amounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Product Information [Line Items]
Management, transaction, and other fees		$ 40,337	$ 26,501	$ 29,636
Property management services [Member]
Product Information [Line Items]
Management, transaction, and other fees		$ 14,415	14,444	14,744
Timing of satisfaction of performance obligations		Over time
Asset management services [Member]
Product Information [Line Items]
Management, transaction, and other fees		$ 6,921	6,963	7,135
Timing of satisfaction of performance obligations		Over time
Promote income [Member]
Product Information [Line Items]
Management, transaction, and other fees	[1]	$ 13,589
Timing of satisfaction of performance obligations		Over time
Leasing services [Member]
Product Information [Line Items]
Management, transaction, and other fees		$ 4,096	3,150	3,692
Timing of satisfaction of performance obligations		Point in time
Other transaction fees [Member]
Product Information [Line Items]
Management, transaction, and other fees		$ 1,316	$ 1,944	$ 4,065
Timing of satisfaction of performance obligations		Point in time

[1] The Company recognized $13.6 million in promote revenue during the year ended December 31, 2021, for exceeding partnership return thresholds from the Company's performance as managing member in the USAA partnership. The consideration was paid in the form of a real estate asset.