Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Parent Company [Member]
Cash flows from operating activities:
Consolidated net income	$ 208,550	$ 49,100
Adjustments to reconcile net income to net cash provided by operating activities:
Retail revenue accretion	(820)	(12)
Depreciation and amortization	149,587	162,099
Stock compensation expense	2,763	2,045
Redeemable stock issued	560	507
Amortization of debt premium	(10,339)	(14,648)
(Gain) loss from investments in real estate joint ventures	6	(2,878)
Loss on debt extinguishment	2,785	0
Derivative interest (credit) expense	(1,021)	402
Gain (Loss) on Sale of Derivatives	0	(3,625)
Gain on sale of non-depreciable real estate assets	(172)	(535)
Gain on sale of depreciable real estate assets excluded from discontinued operations	(135,410)	(6,222)
Gain on sale of discontinued operations	0	(5,481)
Net casualty loss and other settlement proceeds	(490)	308
Changes in assets and liabilities:
Restricted cash	1,720	(5,183)
Other assets	8,562	11,134
Accounts payable	344	229
Accrued expenses and other	(1,204)	594
Security deposits	1,109	526
Net cash provided by operating activities	226,530	188,360
Cash flows from investing activities:
Purchases of real estate and other assets	(161,892)	(141,795)
Normal capital improvements	(48,099)	(45,695)
Construction capital and other improvements	(3,873)	(5,271)
Renovations to existing real estate assets	(12,747)	(7,801)
Development	(14,420)	(46,346)
Distributions from real estate joint ventures	6	11,541
Contributions to Real Estate Joint Ventures	(30)	0
Proceeds from disposition of real estate assets	238,849	125,640
(Funding) return of escrow for future acquisitions	(26,945)	(16,742)
Net cash (used in) provided by investing activities	(29,151)	(126,469)
Cash flows from financing activities:
Net change in credit lines	(16,115)	(181,183)
Proceeds from notes payable	0	396,180
Principal payments on notes payable	(55,199)	(230,952)
Payment of deferred financing costs	(178)	(3,395)
Repurchase of common stock	(945)	(336)
Proceeds from issuances of common shares	184	575
Exercise of stock options	420	9,544
Distributions to noncontrolling interests	(6,443)	(6,158)
Dividends paid on common shares	(115,726)	(109,414)
Net cash used in financing activities	(194,002)	(125,139)
Net (decrease) increase in cash and cash equivalents	3,377	(63,248)
Cash and cash equivalents, beginning of period	26,653	89,333
Cash and cash equivalents, end of period	30,030	26,085
Supplemental disclosure of cash flow information:
Interest paid	71,596	75,818
Income Taxes Paid	2,051	1,596
Supplemental disclosure of noncash investing and financing activities:
Conversion of units to shares of common stock	184	799
Accrued construction in progress	11,165	8,458
Interest capitalized	964	850
Marked-to-market adjustment on derivative instruments	2,484	1,633
Fair value adjustment on debt assumed	0	1,651
Loan assumption	0	31,692
Limited Partner [Member]
Cash flows from operating activities:
Consolidated net income	208,550	49,100
Adjustments to reconcile net income to net cash provided by operating activities:
Retail revenue accretion	(820)	(12)
Depreciation and amortization	149,587	162,099
Stock compensation expense	2,763	2,045
Redeemable stock issued	560	507
Amortization of debt premium	(10,339)	(14,648)
(Gain) loss from investments in real estate joint ventures	6	(2,878)
Loss on debt extinguishment	2,785	0
Derivative interest (credit) expense	(1,021)	402
Gain (Loss) on Sale of Derivatives	0	(3,625)
Gain on sale of non-depreciable real estate assets	(172)	(535)
Gain on sale of depreciable real estate assets excluded from discontinued operations	(135,410)	(6,222)
Gain on sale of discontinued operations	0	(5,481)
Net casualty loss and other settlement proceeds	(490)	308
Changes in assets and liabilities:
Restricted cash	1,720	(5,183)
Other assets	8,562	11,134
Accounts payable	344	229
Accrued expenses and other	(1,204)	594
Security deposits	1,109	526
Net cash provided by operating activities	226,530	188,360
Cash flows from investing activities:
Purchases of real estate and other assets	(161,892)	(141,795)
Normal capital improvements	(48,099)	(45,695)
Construction capital and other improvements	(3,873)	(5,271)
Renovations to existing real estate assets	(12,747)	(7,801)
Development	(14,420)	(46,346)
Distributions from real estate joint ventures	6	11,541
Contributions to Real Estate Joint Ventures	(30)	0
Proceeds from disposition of real estate assets	238,849	125,640
(Funding) return of escrow for future acquisitions	(26,945)	(16,742)
Net cash (used in) provided by investing activities	(29,151)	(126,469)
Cash flows from financing activities:
Net change in credit lines	(16,115)	(181,183)
Proceeds from notes payable	0	396,180
Principal payments on notes payable	(55,199)	(230,952)
Payment of deferred financing costs	(178)	(3,395)
Repurchase of common units	(945)	(336)
Proceeds from issuances of common units	184	575
Exercise of stock options	420	9,544
Distributions paid on common units	(122,169)	(115,572)
Net cash used in financing activities	(194,002)	(125,139)
Net (decrease) increase in cash and cash equivalents	3,377	(63,248)
Cash and cash equivalents, beginning of period	26,653	89,333
Cash and cash equivalents, end of period	30,030	26,085
Supplemental disclosure of cash flow information:
Interest paid	71,596	75,818
Income Taxes Paid	2,051	1,596
Supplemental disclosure of noncash investing and financing activities:
Accrued construction in progress	11,165	8,458
Interest capitalized	964	850
Marked-to-market adjustment on derivative instruments	2,484	1,633
Fair value adjustment on debt assumed	0	1,651
Loan assumption	$ 0	$ 31,692