Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 451,123	$ 447,080	$ 514,222
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	219,857	209,050	193,296
Amortization of deferred financing costs	11,989	14,286	12,289
Non-cash interest expense related to amortization of discount on equity component of exchangeable senior notes	4,742	4,687	5,103
Non-cash lease expense	1,064
Compensation expense related to stock-based awards	13,051	11,176	9,561
Gain on real estate transactions and impairment of real estate	(1,205)	(30,807)	(112,789)
Distributions from unconsolidated real estate ventures in excess of earnings	6,358	6,867	4,567
Changes in operating assets and liabilities:
Other assets	(12,482)	(1,664)	(12,728)
Accounts payable and accrued expenses	15,522	2,736	(10,515)
Other liabilities	(2,333)	14,384	(5,631)
Net cash provided by operating activities	707,686	677,795	597,375
Cash flows from investing activities:
Acquisition of real estate assets	(349,494)	(426,388)	(653,185)
Development and redevelopment of real estate assets	(53,717)	(60,677)	(31,746)
Proceeds from sale of real estate assets	11,254	52,458	312,165
Investment in unconsolidated real estate entities	(197,759)	(65,500)	(17,944)
Return of investment in unconsolidated real estate ventures	3,982	49,130	581
Issuance of notes receivable	(185,993)	(13,850)	0
Principal payments received from notes receivable	157,861	25,226	44,869
Purchase of equipment and fixtures	(7,764)	(4,297)	(7,819)
Net cash used in investing activities	(621,630)	(443,898)	(353,079)
Cash flows from financing activities:
Proceeds from the sale of common stock, net of offering costs	198,827	90,231	0
Proceeds from notes payable and revolving lines of credit	2,214,000	1,413,030	1,325,623
Principal payments on notes payable and revolving lines of credit	(1,977,805)	(1,109,854)	(1,088,679)
Principal payments on notes payable to trusts	(30,928)	(88,662)	0
Deferred financing costs	(2,986)	(12,302)	(6,967)
Repurchase of exchangeable senior notes	0	(80,270)	(19,916)
Net proceeds from exercise of stock options	3,063	1,169	1,266
Redemption of Operating Partnership units held by noncontrolling interests	0	(2,558)	(2,510)
Contributions from noncontrolling interests	173	122	201
Dividends paid on common stock	(458,114)	(424,907)	(393,040)
Distributions to noncontrolling interests	(34,243)	(33,250)	(31,972)
Net cash used in financing activities	(88,013)	(247,251)	(215,994)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(1,957)	(13,354)	28,302
Cash, cash equivalents, and restricted cash, beginning of the period	72,690	86,044	57,742
Cash, cash equivalents, and restricted cash, end of the period	70,733	72,690	86,044
Supplemental schedule of cash flow information
Interest paid	174,155	159,474	136,202
Income taxes paid	10,359	730	5,648
Redemption of Operating Partnership units held by noncontrolling interests for common stock
Noncontrolling interests in Operating Partnership	(13,057)	(1,337)
Common stock and paid-in capital	13,057	1,337
Establishment of operating lease right of use assets and lease liabilities
Real estate assets - operating lease right-of-use assets	277,557
Operating lease liabilities	(286,914)
Accounts payable and accrued expenses	9,357
Acquisitions of real estate assets
Real estate assets, net	21,066	88,842	51,455
Value of Operating Partnership units issued		(1,877)	(14,428)
Notes payable assumed	(17,157)	(87,500)	(24,055)
Investment in unconsolidated real estate ventures	(2,780)	535	(12,957)
Other noncontrolling interests			(15)
Net liabilities assumed	(1,129)
Accrued construction costs and capital expenditures
Acquisition of real estate assets	2,203	778	3,509
Development and redevelopment of real estate assets	1,601	554	1,703
Accounts payable and accrued expenses	(3,804)	(1,332)	(5,212)
Contribution/Issuance of Preferred OP Units for additional investment in unconsolidated real estate venture
Investments in unconsolidated real estate ventures	(28,022)
Preferred OP Units issued	(28,022)		(4,351)
Investment in unconsolidated real estate ventures			$ 4,351
Conversion of Preferred OP Units to common OP Units
Preferred OP Units	4,374	6,851
Common OP Units	$ (4,374)	$ (6,851)