Consolidated Statements Of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income	$ 105,462,000	$ 148,148,000
Changes in operating assets and liabilities:
Depreciation	61,499,000	62,126,000
Amortization of Debt Issuance Costs	3,281,000	3,775,000
Amortization of commitment fees	(645,000)	(581,000)
Amortization of lease incentives	774,000	735,000
Straight-line rental income	(12,189,000)	(15,481,000)
Non-cash interest income on construction loan	(1,351,000)	(2,865,000)
Gains (Losses) on Sales of Investment Real Estate	(26,426,000)	(21,007,000)
Income (Loss) from Equity Method Investments	2,274,000	2,018,000
Gain (Loss) on Extinguishment of Debt	451,000	0
Loan and realty losses	23,596,000	1,002,000
Payment of Tenant Lease Incentives	(1,042,000)	(498,000)
Share-based compensation	7,427,000	2,772,000
Change in operating assets and liabilities:
Other assets	(3,138,000)	(835,000)
Accounts payable and accrued expenses	(2,591,000)	(2,513,000)
Deferred income	119,000	(269,000)
Net cash provided by operating activities	157,501,000	176,527,000
Cash flows from investing activities:
Investment in mortgage and other notes receivable	(54,887,000)	(41,715,000)
Collection of mortgage and other notes receivable	64,509,000	33,895,000
Investment in real estate	(46,817,000)	(102,712,000)
Proceeds from Sale of Wholly Owned Real Estate and Real Estate Acquired in Settlement of Loans	203,147,000	39,260,000
Payments to Renovate Real Estate	(3,006,000)	(11,113,000)
Payments to Develop Real Estate Assets	(64,000)	(158,000)
Payments to Acquire Equity Method Investments	0	(875,000)
Proceeds from Equity Method Investment, Distribution	476,000	0
Net cash used in investing activities	163,358,000	(83,418,000)
Cash flows from financing activities:
Proceeds from revolving credit facilities	95,000,000	145,000,000
Payments on revolving credit facilities	(393,000,000)	(157,000,000)
Borrowings on term loan	0	100,000,000
Repayments of Long-term Debt	(250,277,000)	(917,000)
Proceeds from Issuance of Senior Long-term Debt	396,784,000	0
Debt issuance costs	(5,018,000)	(1,039,000)
Proceeds from issuance of common shares, net	47,904,000	4,791,000
Payments to Noncontrolling Interests	(692,000)	(537,000)
Payments for Repurchase of Redeemable Convertible Preferred Stock	(66,076,000)	0
Dividends paid to stockholders	(141,632,000)	(145,270,000)
Value of shares withheld from options exercised for employee tax withholding	0	(2,705,000)
Proceeds from Noncontrolling Interests	0	13,000
Net cash provided by (used in) financing activities	(317,007,000)	(57,664,000)
Increase in cash and cash equivalents and restricted cash	3,852,000	35,445,000
Cash and cash equivalents and restricted cash, beginning of period	50,195,000	51,114,000
Supplemental disclosure of cash flow information:
Interest paid, net of amounts capitalized	34,991,000	33,174,000
Supplemental schedule of non-cash investing and financing activities:
Change in mortgage notes receivable related to investments in real estate		63,220,000
Noncontrolling Interest, Noncash Increase from Subsidiary Equity Issuance		10,778,000
Increase in mortgage note receivable from sale of real estate		4,000,000
Change in other assets related to investments in real estate		348,000
Noncash or Part Noncash Acquisition, Other Assets Acquired	12,814,000
Change in accounts payable related to investments in real estate construction	(112,000)	(1,744,000)
Change in accounts payable related to distributions to noncontrolling interests	$ 5,000	85,000
Change in Accounts Payable, Renovations of existing real estate		$ 355,000