Organization and Significant Accounting Policies - Revenues and Tenant and Other Receivables (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2021		Sep. 30, 2020	Sep. 30, 2021		Sep. 30, 2020	Dec. 31, 2020
Schedule of management, transaction, and other fees [Line Items]
Management, transaction, and other fees	$ 19,671		$ 6,142	$ 33,419		$ 19,084
Tenant and other receivables	139,287			139,287			$ 143,633
Management, transaction, and other fee [Member]
Schedule of management, transaction, and other fees [Line Items]
Tenant and other receivables	11,400			11,400			$ 9,900
Property management services [Member]
Schedule of management, transaction, and other fees [Line Items]
Management, transaction, and other fees	3,450		3,598	10,974		10,830
Asset management services [Member]
Schedule of management, transaction, and other fees [Line Items]
Management, transaction, and other fees	1,709		1,657	5,143		5,250
Leasing services [Member]
Schedule of management, transaction, and other fees [Line Items]
Management, transaction, and other fees	879		708	3,066		1,948
Other transaction fees [Member]
Schedule of management, transaction, and other fees [Line Items]
Management, transaction, and other fees	$ 13,633	[1]	$ 179	$ 14,236	[1]	$ 1,056

[1] Includes $13.6 million of promote income earned for exceeding partnership return thresholds resulting from the Company's performance as managing member. This consideration was paid in the form of a real estate asset. See note 2.