Summary of Significant Accounting Policies - Schedule of Unpaid Claims Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Tenant Reinsurance Claims:
Unpaid claims liability at beginning of year	$ 8,109	$ 7,326	$ 5,167
Claims and claim adjustment expense for claims incurred in the current year	14,534	16,280	15,800
Claims and claim adjustment expense (benefit) for claims incurred in the prior years	(1,351)	98	107
Payments for current year claims	(9,697)	(11,352)	(11,010)
Payments for prior year claims	(3,301)	(4,243)	(2,738)
Unpaid claims liability at the end of the year	$ 8,294	$ 8,109	$ 7,326