CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 452,093,000	$ 492,866,000	$ 272,908,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	16,162,000	23,782,000	40,386,000
Net amortization of debt discounts, premiums and deferred financing fees	(119,000)	204,000	2,553,000
Straight-line rental income	340,000	(418,000)	(4,971,000)
Amortization of acquired real estate leases	0	158,000	2,187,000
Other amortization	3,167,000	4,009,000	6,127,000
Amortization of right-of-use asset	767,000	736,000	0
Share-based compensation	13,215,000	14,426,000	19,697,000
Loss on asset impairment	0	0	12,087,000
(Gain) loss on early extinguishment of debt	(131,000)	6,374,000	7,122,000
Loss on sale of marketable securities	0	0	4,987,000
Net gain on sale of properties	(446,744,000)	(422,172,000)	(251,417,000)
Loss on sale of real estate mortgage receivable	0	0	2,117,000
Change in assets and liabilities:
Rents receivable and other assets	(2,119,000)	(13,099,000)	(19,886,000)
Accounts payable, accrued expenses and other	(3,104,000)	(5,311,000)	(704,000)
Rent collected in advance	(199,000)	(2,610,000)	(3,657,000)
Net cash provided by operating activities	33,328,000	98,945,000	89,536,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Real estate improvements	(12,039,000)	(26,052,000)	(49,930,000)
Insurance proceeds received	0	0	1,443,000
Proceeds from sale of properties, net	655,291,000	771,787,000	961,079,000
Proceeds from sale of real estate mortgage receivable	0	0	5,599,000
Proceeds from sale of marketable securities	0	0	23,933,000
Proceeds from maturity of marketable securities	0	250,000,000	0
Net cash provided by investing activities	643,252,000	995,735,000	942,124,000
CASH FLOWS FROM FINANCING ACTIVITIES:
Repurchase and retirement of common shares	(26,897,000)	(5,487,000)	(93,976,000)
Payments on borrowings	(25,441,000)	(255,842,000)	(581,460,000)
Contributions from holders of noncontrolling interest	1,000	0	1,000
Distributions to common shareholders	(427,795,000)	(428,649,000)	(304,612,000)
Distributions to preferred shareholders	(7,988,000)	(7,988,000)	(7,988,000)
Distributions to holders of noncontrolling interest	(1,849,000)	(170,000)	(114,000)
Redemption of noncontrolling interest	(31,000)	0	0
Net cash used in financing activities	(490,000,000)	(698,136,000)	(988,149,000)
Increase in cash, cash equivalents, and restricted cash	186,580,000	396,544,000	43,511,000
Cash, cash equivalents, and restricted cash at beginning of year	2,800,645,000	2,404,101,000	2,360,590,000
Cash, cash equivalents, and restricted cash at end of year	2,987,225,000	2,800,645,000	2,404,101,000
SUPPLEMENTAL CASH FLOW INFORMATION:
Interest paid	843,000	13,032,000	27,117,000
Taxes paid, net	1,444,000	2,933,000	2,264,000
NON-CASH INVESTING ACTIVITIES:
Recognition of right-of-use asset and lease liability	0	1,503,000
Accrued capital expenditures	986,000	1,383,000	13,540,000
NON-CASH FINANCING ACTIVITIES:
Total cash, cash equivalents, and restricted cash shown in the statement of cash flows	$ 2,800,645,000	$ 2,800,645,000	$ 2,360,590,000