Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net income	$ 306,673	$ 197,792
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	133,402	92,691
Amortization of deferred financing costs	9,388	4,876
Non-cash interest expense related to amortization of discount on equity component of exchangeable senior notes	3,716	2,198
Non-cash interest expense related to amortization of premium on notes payable	(828)	(2,046)
Compensation expense related to stock-based awards	6,008	4,385
Gain on sale of real estate assets and purchase of joint venture partners' interests	(64,432)	(2,857)
Gain on real estate transactions and earnout from prior acquisition	(9,814)	(1,501)
Distributions from unconsolidated real estate ventures in excess of earnings	3,071	4,020
Changes in operating assets and liabilities:
Receivables from related parties and affiliated real estate joint ventures	923	(2,247)
Other assets	(16,059)	(20,022)
Accounts payable and accrued expenses	10,938	10,782
Other liabilities	3,173	(1,790)
Net cash provided by operating activities	386,159	286,281
Cash flows from investing activities:
Acquisition of real estate assets	(763,246)	(263,404)
Development and redevelopment of real estate assets	(18,492)	(15,137)
Proceeds from sale of real estate assets	56,786	800
Change in restricted cash	14,296	(203,384)
Investment in unconsolidated real estate ventures	(25,690)	(549)
Return of investment in unconsolidated real estate ventures	11,991	61
Purchase/issuance of notes receivable	(18,530)	0
Principal payments received from notes receivable	41,393	0
Purchase of equipment and fixtures	(2,818)	(4,821)
Net cash used in investing activities	(704,310)	(486,434)
Cash flows from financing activities:
Proceeds from the sale of common stock, net of offering costs	123,423	446,909
Net proceeds from the issuance of exchangeable senior notes	0	563,500
Repurchase of exchangeable senior notes	(22,192)	(227,212)
Proceeds from notes payable and lines of credit	1,026,975	1,718,753
Principal payments on notes payable and lines of credit	(565,541)	(1,016,064)
Deferred financing costs	(6,700)	(5,138)
Net proceeds from exercise of stock options	312	1,424
Proceeds from termination of interest rate cap	1,650	0
Payment of earnout from prior acquisition	(4,600)	0
Dividends paid on common stock	(269,630)	(196,076)
Distributions to noncontrolling interests	(22,653)	(18,074)
Net cash provided by financing activities	261,044	1,268,022
Net decrease in cash and cash equivalents	(57,107)	1,067,869
Cash and cash equivalents, beginning of the period	75,799	47,663
Cash and cash equivalents, end of the period	18,692	1,115,532
Supplemental schedule of cash flow information
Interest paid	94,585	60,040
Income taxes paid	10,813	1,555
Redemption of Operating Partnership units held by noncontrolling interests for common stock:
Noncontrolling interests in Operating Partnership	(839)	(150)
Common stock and paid-in capital	839	150
Tax effect from vesting of restricted stock grants and option exercises:
Other assets	1,322	1,563
Additional paid-in capital	(1,322)	(1,563)
Acquisitions of real estate assets:
Operating Partnership units issued	(56,237)
Accrued construction costs and capital expenditures:
Acquisition of real estate assets	8,839	0
Accounts payable and accrued expenses	(8,839)	0
Distribution of real estate from investments in unconsolidated real estate ventures:
Real estate assets, net	21,587	0
Investments in unconsolidated real estate ventures	(21,587)	0
Disposition of real estate assets:
Real estate assets, net	(7,689)	0
Redemption of Operating Partnership Units [Member]
Disposition of real estate assets:
Operating Partnership units redeemed	7,689	0
Acquisitions Of Real Estate [Member]
Acquisitions of real estate assets:
Real estate assets, net	65,960	122,132
Operating Partnership units issued	(56,237)	(106,522)
Notes payable assumed	(9,723)	0
Receivables from related parties and affiliated real estate joint ventures	0	(15,610)
Acquisition Of Other Noncontrolling Interests [Member]
Acquisition of other noncontrolling interests:
Operating Partnership units issued	(800)	0
Other noncontrolling interests	162	0
Additional paid-in capital	$ 638	$ 0