CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income (loss)	$ 525,930	$ 428,253	$ 60,061
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization of real estate, in-place lease, and other intangibles	684,286	697,143	659,989
Amortization of stock-based compensation	18,202	17,368	18,162
Amortization of deferred financing costs	9,216	10,157	10,863
Straight-line rents	(31,188)	(24,532)	(22,479)
Amortization of nonrefundable entrance fees and above/below market lease intangibles	(94,362)	(81,914)	0
Equity loss (income) from unconsolidated joint ventures	(11,235)	67,787	8,625
Distributions of earnings from unconsolidated joint ventures	4,976	12,294	20,114
Loss (gain) on sale of real estate under direct financing leases	0	(41,670)	0
Deferred income tax expense (benefit)	(5,792)	(14,573)	(18,253)
Impairments and loan loss reserves (recoveries), net	55,896	244,253	225,937
Loss (gain) on debt extinguishments	225,824	42,912	58,364
Loss (gain) on sales of real estate, net	(605,311)	(550,494)	(22,900)
Loss (gain) upon change of control, net	(1,042)	(159,973)	(168,023)
Casualty-related loss (recoveries), net	1,632	469	(3,706)
Other non-cash items	(8,178)	2,175	(2,569)
Changes in:
Decrease (increase) in accounts receivable and other assets, net	18,626	15,281	(49,771)
Increase (decrease) in accounts payable, accrued liabilities, and deferred revenue	7,768	93,495	71,659
Net cash provided by (used in) operating activities	795,248	758,431	846,073
Cash flows from investing activities:
Acquisitions of real estate	(1,483,026)	(1,170,651)	(1,604,285)
Development, redevelopment, and other major improvements of real estate	(610,555)	(791,566)	(626,904)
Leasing costs, tenant improvements, and recurring capital expenditures	(111,480)	(94,121)	(108,844)
Proceeds from sales of real estate, net	2,399,120	1,304,375	230,455
Acquisition of CCRC Portfolio	0	(394,177)	0
Contributions to unconsolidated joint ventures	(25,260)	(39,118)	(14,956)
Distributions in excess of earnings from unconsolidated joint ventures	37,640	18,555	27,072
Proceeds from insurance recovery	0	1,802	9,359
Proceeds from the U.K. JV transaction, net	0	0	89,868
Proceeds from the Sovereign Wealth Fund Senior Housing JV transaction, net	0	0	354,774
Proceeds from sales/principal repayments on loans receivable and direct financing leases	342,420	202,763	274,150
Investments in loans receivable and other	(17,827)	(45,562)	(79,467)
Net cash provided by (used in) investing activities	531,032	(1,007,700)	(1,448,778)
Cash flows from financing activities:
Borrowings under bank line of credit and commercial paper	16,821,450	4,742,600	7,607,788
Repayments under bank line of credit and commercial paper	(15,785,065)	(4,706,010)	(7,597,047)
Issuance and borrowings of debt, excluding bank line of credit and commercial paper	1,088,537	594,750	2,047,069
Repayments and repurchase of debt, excluding bank line of credit and commercial paper	(2,425,936)	(568,343)	(1,654,142)
Borrowings under term loan	0	0	250,000
Payments for debt extinguishment and deferred financing costs	(236,942)	(47,210)	(80,616)
Issuance of common stock and exercise of options	5,036	1,068,877	795,586
Repurchase of common stock	(12,841)	(10,529)	(5,043)
Dividends paid on common stock	(650,082)	(787,072)	(720,123)
Contributions from and issuance of noncontrolling interests	640	0	33,318
Distributions to and purchase of noncontrolling interests	(93,314)	(40,613)	(29,519)
Net cash provided by (used in) financing activities	(1,288,517)	246,450	647,271
Effect of foreign exchanges on cash, cash equivalents and restricted cash	0	(153)	245
Net increase (decrease) in cash, cash equivalents and restricted cash	37,763	(2,972)	44,811
Cash, cash equivalents and restricted cash, beginning of year	181,685	184,657	139,846
Cash, cash equivalents and restricted cash, end of year	$ 219,448	$ 181,685	$ 184,657