Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income	$ 284,907	$ 306,673
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	144,139	133,402
Amortization of deferred financing costs	9,246	9,388
Non-cash interest expense related to amortization of discount on equity component of exchangeable senior notes	3,827	3,716
Non-cash interest expense related to amortization of premium on notes payable	0	(828)
Compensation expense related to stock-based awards	7,244	6,008
Gain on sale of real estate assets and purchase of joint venture partner's interest	0	(64,432)
(Gain) loss on real estate transactions, earnout from prior acquisition and impairment of real estate	6,019	(9,814)
Distributions from unconsolidated real estate ventures in excess of earnings	3,498	3,071
Changes in operating assets and liabilities:
Receivables from related parties and affiliated real estate joint ventures	195	923
Other assets	(15,498)	(16,059)
Accounts payable and accrued expenses	6,425	10,938
Other liabilities	(373)	3,173
Net cash provided by operating activities	449,629	386,159
Cash flows from investing activities:
Acquisition of real estate assets	(119,040)	(763,246)
Development and redevelopment of real estate assets	(20,670)	(18,492)
Proceeds from sale of real estate assets, investments in real estate ventures and other assets	18,565	56,786
Change in restricted cash	(3,393)	14,296
Investment in unconsolidated real estate ventures	(3,021)	(25,690)
Return of investment in unconsolidated real estate ventures	581	11,991
Purchase/issuance of notes receivable	0	(18,530)
Principal payments received from notes receivable	44,869	41,393
Purchase of equipment and fixtures	(5,635)	(2,818)
Net cash used in investing activities	(87,744)	(704,310)
Cash flows from financing activities:
Proceeds from the sale of common stock, net of offering costs	0	123,423
Repurchase of exchangeable senior notes	(19,726)	(22,192)
Proceeds from notes payable and revolving lines of credit	1,023,170	1,026,975
Principal payments on notes payable and revolving lines of credit	(1,020,144)	(565,541)
Deferred financing costs	(5,172)	(6,700)
Net proceeds from exercise of stock options	1,266	312
Proceeds from termination of interest rate cap	0	1,650
Payment of earnout from prior acquisition	0	(4,600)
Redemption of Operating Partnership units held by noncontrolling interests	(2,510)	0
Dividends paid on common stock	(294,754)	(269,630)
Distributions to noncontrolling interests	(24,141)	(22,653)
Net cash provided by (used in) financing activities	(342,011)	261,044
Net increase in cash and cash equivalents	19,874	(57,107)
Cash and cash equivalents, beginning of the period	43,858	75,799
Cash and cash equivalents, end of the period	63,732	18,692
Supplemental schedule of cash flow information
Interest paid	107,144	94,585
Income taxes paid	8,086	10,813
Redemption of Operating Partnership units held by noncontrolling interests for common stock:
Noncontrolling interests in Operating Partnership	0	(839)
Common stock and paid-in capital	0	839
Tax effect from vesting of restricted stock grants and option exercises
Other assets	0	1,322
Additional paid-in capital	0	(1,322)
Accrued construction costs and capital expenditures
Acquisition of real estate assets	4,874	8,839
Development and redevelopment of real estate assets	1,558	0
Other liabilities	(6,432)	(8,839)
Distribution of real estate from investments in unconsolidated real estate ventures
Real estate assets, net	0	21,587
Investments in unconsolidated real estate ventures	0	(21,587)
Disposition of real estate assets
Real estate assets, net	0	(7,689)
Acquisitions Of Real Estate [Member]
Acquisitions of real estate assets
Real estate assets, net	20,100	65,960
Value of Operating Partnership units issued	(8,810)	(56,237)
Notes payable assumed	(9,463)	(9,723)
Other noncontrolling interests	(1,827)	0
Redemption Of Operating Partnership Units [Member]
Disposition of real estate assets
Operating Partnership units redeemed	0	7,689
Acquisition Of Other Noncontrolling Interests [Member]
Acquisition of noncontrolling interests
Operating Partnership units issued	0	(800)
Other noncontrolling interests	0	162
Additional paid-in capital	$ 0	$ 638