Condensed Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Parent Company [Member]
Cash flows from operating activities:
Consolidated net income	$ 212,529,000	$ 182,344,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, Amortization and Accretion, Net	(292,000)	(130,000)
Depreciation and amortization	(374,947,000)	(228,073,000)
Stock compensation expense	8,431,000	5,977,000
Redeemable stock issued	489,000	412,000
Amortization of debt premium	(8,035,000)	(7,546,000)
(Gain) loss from investments in real estate joint ventures	(1,021,000)	(27,000)
Loss on debt extinguishment	(4,753,000)	0
Derivative interest (credit) expense	(9,298,000)	(1,883,000)
Gain on sale of non-depreciable real estate assets	(42,000)	(2,170,000)
Gain on sale of depreciable real estate assets excluded from discontinued operations	(59,045,000)	(48,572,000)
Net casualty loss and other settlement proceeds	(233,000)	(738,000)
Settlement of Forward Swaps	(1,547,000)	0
Changes in assets and liabilities:
Restricted cash	(2,580,000)	(4,955,000)
Other assets	(6,264,000)	(501,000)
Accounts payable	(5,305,000)	(3,158,000)
Accrued expenses and other	44,353,000	35,183,000
Security deposits	164,000	597,000
Net cash provided by operating activities	553,108,000	389,222,000
Cash flows from investing activities:
Net (decrease) increase in cash and cash equivalents	14,315,000	(9,742,000)
Purchases of real estate and other assets	(63,774,000)	(262,268,000)
Normal capital improvements	(82,030,000)	(65,351,000)
Construction capital and other improvements	(7,171,000)	(5,569,000)
Renovations to existing real estate assets	(36,692,000)	(29,554,000)
Development	(142,530,000)	(42,611,000)
Distributions from real estate joint ventures	0	1,823,000
Contributions to Real Estate Joint Ventures	(750,000)	0
Proceeds from disposition of real estate assets	90,040,000	187,425,000
(Funding) return of escrow for future acquisitions	10,591,000	0
Net cash (used in) provided by investing activities	(232,316,000)	(216,105,000)
Cash flows from financing activities:
Net change in credit lines	(240,000,000)	130,000,000
Proceeds from notes payable	597,480,000	0
Principal payments on notes payable	(345,053,000)	(114,753,000)
Payment of deferred financing costs	(5,355,000)	(141,000)
Repurchase of common stock	(4,782,000)	(1,811,000)
Proceeds from issuances of common shares	1,007,000	(216,000)
Proceeds from Stock Options Exercised	432,000	0
Distributions to noncontrolling interests	(10,999,000)	(10,234,000)
Dividends paid on common shares	(296,441,000)	(185,704,000)
Dividends, Preferred Stock, Cash	(2,766,000)	0
Net cash used in financing activities	(306,477,000)	(182,859,000)
Cash and cash equivalents, beginning of period	33,536,000	37,559,000
Cash and cash equivalents, end of period	47,851,000	27,817,000
Supplemental disclosure of cash flow information:
Interest paid	123,735,000	96,271,000
Income Taxes Paid	2,256,000	1,571,000
Supplemental disclosure of noncash investing and financing activities:
Conversion of units to shares of common stock	1,133,000	780,000
Accrued construction in progress	15,787,000	8,742,000
Interest capitalized	5,884,000	1,095,000
Marked To Market Adjustment On Derivative Instruments	12,035,000	1,402,000
Limited Partner [Member]
Cash flows from operating activities:
Consolidated net income	212,529,000	182,344,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, Amortization and Accretion, Net	(292,000)	(130,000)
Depreciation and amortization	(374,947,000)	(228,073,000)
Stock compensation expense	8,431,000	5,977,000
Redeemable stock issued	489,000	412,000
Amortization of debt premium	(8,035,000)	(7,546,000)
(Gain) loss from investments in real estate joint ventures	(1,021,000)	(27,000)
Loss on debt extinguishment	(4,753,000)	0
Derivative interest (credit) expense	(9,298,000)	(1,883,000)
Gain on sale of non-depreciable real estate assets	(42,000)	(2,170,000)
Gain on sale of depreciable real estate assets excluded from discontinued operations	(59,045,000)	(48,572,000)
Net casualty loss and other settlement proceeds	(233,000)	(738,000)
Settlement of Forward Swaps	(1,547,000)	0
Changes in assets and liabilities:
Restricted cash	(2,580,000)	(4,955,000)
Other assets	(6,264,000)	(501,000)
Accounts payable	(5,305,000)	(3,158,000)
Accrued expenses and other	44,353,000	35,183,000
Security deposits	164,000	597,000
Net cash provided by operating activities	553,108,000	389,222,000
Cash flows from investing activities:
Net (decrease) increase in cash and cash equivalents	14,315,000	(9,742,000)
Purchases of real estate and other assets	(63,774,000)	(262,268,000)
Normal capital improvements	(82,030,000)	(65,351,000)
Construction capital and other improvements	(7,171,000)	(5,569,000)
Renovations to existing real estate assets	(36,692,000)	(29,554,000)
Development	(142,530,000)	(42,611,000)
Distributions from real estate joint ventures	0	1,823,000
Contributions to Real Estate Joint Ventures	(750,000)	0
Proceeds from disposition of real estate assets	90,040,000	187,425,000
(Funding) return of escrow for future acquisitions	10,591,000	0
Net cash (used in) provided by investing activities	(232,316,000)	(216,105,000)
Cash flows from financing activities:
Net change in credit lines	(240,000,000)	130,000,000
Proceeds from notes payable	597,480,000	0
Principal payments on notes payable	(345,053,000)	(114,753,000)
Payment of deferred financing costs	(5,355,000)	(141,000)
Repurchase of common units	(4,782,000)	(1,811,000)
Proceeds from issuances of common units	1,007,000	(216,000)
Proceeds from Stock Options Exercised	432,000	0
Distributions paid on common units	(307,440,000)	(195,938,000)
Dividends, Preferred Stock, Cash	(2,766,000)	0
Net cash used in financing activities	(306,477,000)	(182,859,000)
Cash and cash equivalents, beginning of period	33,536,000	37,559,000
Cash and cash equivalents, end of period	47,851,000	27,817,000
Supplemental disclosure of cash flow information:
Interest paid	123,735,000	96,271,000
Income Taxes Paid	2,256,000	1,571,000
Supplemental disclosure of noncash investing and financing activities:
Accrued construction in progress	15,787,000	8,742,000
Interest capitalized	5,884,000	1,095,000
Marked To Market Adjustment On Derivative Instruments	$ 12,035,000	$ 1,402,000