CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 36,460	$ 23,286	$ 101,300	$ 29,277
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	44,209	43,092	132,579	137,517
Non-cash rental and related revenues			1,340	(12,965)
Non-cash interest income			(1,743)	(1,680)
Non-cash interest expense	2,100	2,500	6,527	7,846
Stock-based compensation expense			5,651	8,829
Non-cash lease termination income			0	(9,725)
Loss on extinguishment of debt	139	644	531	10,763
Provision for loan losses and other reserves	(90)	57	706	1,457
Net gain on sales of real estate	(2,715)	19	(2,828)	(1,216)
Impairment of real estate	3,154	13,966	3,154	119,102
Loss from unconsolidated joint venture	(2,766)	605	13,037	5,635
Distributions of earnings from unconsolidated joint venture			11,318	10,162
Changes in operating assets and liabilities:
Accounts receivable, prepaid expenses and other assets, net			(3,523)	(7,252)
Accounts payable and accrued liabilities			(2,594)	(20,769)
Net cash provided by operating activities			265,455	276,981
Cash flows from investing activities:
Acquisition of real estate			(92,945)	(14,977)
Origination and fundings of loans receivable			(1,651)	(9,441)
Origination and fundings of preferred equity investments			(20,059)	0
Additions to real estate			(32,416)	(15,985)
Repayments of loans receivable			3,095	13,761
Repayments of preferred equity investments			3,399	3,672
Net proceeds from the sales of real estate			8,754	321,715
Distributions in excess of earnings from unconsolidated joint venture			1,305	0
Buyout of noncontrolling interests			0	(200)
Net cash (used in) provided by investing activities			(130,518)	298,545
Cash flows from financing activities:
Net borrowings from (repayments of) revolving credit facility			56,000	(424,000)
Proceeds from issuance of senior unsecured notes			0	297,039
Principal payments on senior unsecured notes			0	(500,000)
Principal payments on secured debt			(2,396)	(2,566)
Payments of deferred financing costs			(819)	(14,001)
Payments related to extinguishment of debt			0	(6,897)
Distributions to noncontrolling interest			0	(116)
Issuance of common stock, net			20,961	302,030
Dividends paid on common stock			(215,747)	(247,222)
Net cash used in financing activities			(142,001)	(595,733)
Net decrease in cash, cash equivalents and restricted cash			(7,064)	(20,207)
Effect of foreign currency translation on cash, cash equivalents and restricted cash			(230)	211
Cash, cash equivalents and restricted cash, beginning of period			49,143	59,658	$ 59,658
Cash, cash equivalents and restricted cash, end of period	$ 41,849	$ 39,662	41,849	39,662	$ 49,143
Supplemental disclosure of cash flow information:
Interest paid			67,995	100,230
Supplemental disclosure of non-cash investing activities:
Decrease in loans receivable and other investments due to acquisition of real estate			20,731	0
Secured debt assumed by buyers in connection with sales of real estate			$ 31,830	$ 0