Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from financing activities:
Dividends, Preferred Stock, Cash		$ 0
Supplemental disclosure of noncash investing and financing activities:
Marked-to-market adjustment on derivative instruments	$ 1,700,000
Parent Company [Member]
Cash flows from operating activities:
Consolidated net income	93,571,000	93,438,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, Amortization and Accretion, Net	(196,000)	(110,000)
Depreciation and amortization	(256,872,000)	(151,114,000)
Stock compensation expense	5,618,000	3,958,000
Redeemable stock issued	330,000	282,000
Amortization of debt premium	(6,023,000)	(5,096,000)
(Gain) loss from investments in real estate joint ventures	(686,000)	(27,000)
Loss on debt extinguishment	(3,921,000)	0
Derivative interest (credit) expense	(4,064,000)	(1,295,000)
Gain on sale of non-depreciable real estate assets	(48,000)	(2,170,000)
Gain on sale of depreciable real estate assets excluded from discontinued operations	(201,000)	(823,000)
Net casualty loss and other settlement proceeds	331,000	(813,000)
Changes in assets and liabilities:
Restricted cash	2,146,000	951,000
Other assets	(6,077,000)	4,130,000
Accounts payable	(2,008,000)	(1,542,000)
Accrued expenses and other	(17,131,000)	(7,567,000)
Security deposits	806,000	702,000
Net cash provided by operating activities	321,788,000	238,216,000
Cash flows from investing activities:
Net (decrease) increase in cash and cash equivalents	6,123,000	(11,280,000)
Purchases of real estate and other assets	(62,817,000)	(130,597,000)
Normal capital improvements	(50,890,000)	(44,417,000)
Construction capital and other improvements	(5,453,000)	(3,288,000)
Renovations to existing real estate assets	(20,309,000)	(17,719,000)
Development	(109,720,000)	(29,156,000)
Distributions from real estate joint ventures	0	1,793,000
Proceeds from disposition of real estate assets	1,551,000	38,001,000
(Funding) return of escrow for future acquisitions	58,259,000	0
Net cash (used in) provided by investing activities	(189,379,000)	(185,383,000)
Cash flows from financing activities:
Net change in credit lines	(330,000,000)	105,000,000
Proceeds from notes payable	597,480,000	0
Principal payments on notes payable	(178,164,000)	(37,261,000)
Payment of deferred financing costs	(5,257,000)	(141,000)
Repurchase of common stock	(4,782,000)	(1,742,000)
Proceeds from issuances of common shares	783,000	628,000
Proceeds from Stock Options Exercised	432,000	0
Distributions to noncontrolling interests	(7,332,000)	(6,823,000)
Dividends paid on common shares	(197,602,000)	(123,774,000)
Dividends, Preferred Stock, Cash	(1,844,000)
Net cash used in financing activities	(126,286,000)	(64,113,000)
Cash and cash equivalents, beginning of period	33,536,000	37,559,000
Cash and cash equivalents, end of period	39,659,000
Supplemental disclosure of cash flow information:
Interest paid	79,981,000	71,092,000
Income Taxes Paid	2,226,000	1,544,000
Supplemental disclosure of noncash investing and financing activities:
Conversion of units to shares of common stock	265,000	158,000
Accrued construction in progress	19,360,000	10,781,000
Interest capitalized	4,227,000	708,000
Marked-to-market adjustment on derivative instruments	6,757,000	(1,407,000)
Settlement of Forward Swaps	(1,547,000)	0
Limited Partner [Member]
Cash flows from operating activities:
Consolidated net income	93,571,000	93,438,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, Amortization and Accretion, Net	(196,000)	(110,000)
Depreciation and amortization	(256,872,000)	(151,114,000)
Stock compensation expense	5,618,000	3,958,000
Redeemable stock issued	330,000	282,000
Amortization of debt premium	(6,023,000)	(5,096,000)
(Gain) loss from investments in real estate joint ventures	(686,000)	(27,000)
Loss on debt extinguishment	(3,921,000)	0
Derivative interest (credit) expense	(4,064,000)	(1,295,000)
Gain on sale of non-depreciable real estate assets	(48,000)	(2,170,000)
Gain on sale of depreciable real estate assets excluded from discontinued operations	(201,000)	(823,000)
Net casualty loss and other settlement proceeds	331,000	(813,000)
Changes in assets and liabilities:
Restricted cash	2,146,000	951,000
Other assets	(6,077,000)	4,130,000
Accounts payable	(2,008,000)	(1,542,000)
Accrued expenses and other	(17,131,000)	(7,567,000)
Security deposits	806,000	702,000
Net cash provided by operating activities	321,788,000	238,216,000
Cash flows from investing activities:
Net (decrease) increase in cash and cash equivalents	6,123,000	(11,280,000)
Purchases of real estate and other assets	(62,817,000)	(130,597,000)
Normal capital improvements	(50,890,000)	(44,417,000)
Construction capital and other improvements	(5,453,000)	(3,288,000)
Renovations to existing real estate assets	(20,309,000)	(17,719,000)
Development	(109,720,000)	(29,156,000)
Distributions from real estate joint ventures	0	1,793,000
Proceeds from disposition of real estate assets	1,551,000	38,001,000
(Funding) return of escrow for future acquisitions	58,259,000	0
Net cash (used in) provided by investing activities	(189,379,000)	(185,383,000)
Cash flows from financing activities:
Net change in credit lines	(330,000,000)	105,000,000
Proceeds from notes payable	597,480,000	0
Principal payments on notes payable	(178,164,000)	(37,261,000)
Payment of deferred financing costs	(5,257,000)	(141,000)
Repurchase of common units	(4,782,000)	(1,742,000)
Proceeds from issuances of common units	783,000	628,000
Proceeds from Stock Options Exercised	432,000	0
Distributions paid on common units	(204,934,000)	(130,597,000)
Dividends, Preferred Stock, Cash	(1,844,000)	0
Net cash used in financing activities	(126,286,000)	(64,113,000)
Cash and cash equivalents, beginning of period	33,536,000	37,559,000
Cash and cash equivalents, end of period	39,659,000	26,279,000
Supplemental disclosure of cash flow information:
Interest paid	79,981,000	71,092,000
Income Taxes Paid	2,226,000	1,544,000
Supplemental disclosure of noncash investing and financing activities:
Accrued construction in progress	19,360,000	10,781,000
Interest capitalized	4,227,000	708,000
Marked-to-market adjustment on derivative instruments	6,757,000	(1,407,000)
Settlement of Forward Swaps	$ (1,547,000)	$ 0