Schedule II - Valuation and Qualifying Accounts - Allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Notes receivable, valuation allowance	$ 1,700	$ 700	$ 2,900
Uncollectible tenant receivables [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	1,171	4,639	2,309
Balance, Beginning of Period, adjusted			512
Charged to Costs and Expenses	1,977	907	2,604
Deductions (3)	(1,349)	(248)	(274)
Balance at End of Period	1,799	1,171	4,639
Allowance for deferred rent [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	1,552	3,339	3,238
Balance, Beginning of Period, adjusted			195
Charged to Costs and Expenses	832	1,357	165
Deductions (3)	(1,580)	0	(64)
Balance at End of Period	$ 804	$ 1,552	$ 3,339