Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Parent Company [Member]
Cash flows from operating activities:
Consolidated net income	$ 64,677	$ 15,714
Adjustments to reconcile net income to net cash provided by operating activities:
Retail revenue accretion	(29)	(6)
Depreciation and amortization	74,034	91,469
Stock compensation expense	1,289	948
Redeemable stock issued	189	145
Amortization of debt premium	(5,197)	(7,402)
(Gain) loss from investments in real estate joint ventures	(17)	24
Loss on debt extinguishment	2,787	0
Derivative interest (credit) expense	(473)	427
Gain on sale of non-depreciable real estate assets	0	(557)
Gain on sale of depreciable real estate assets excluded from discontinued operations	(30,228)	(2,564)
Gain on sale of discontinued operations	0	(5,481)
Net casualty loss and other settlement proceeds	19	12
Changes in assets and liabilities:
Restricted cash	7,391	787
Other assets	2,441	5,664
Accounts payable	(431)	106
Accrued expenses and other	(16,060)	(3,465)
Security deposits	465	240
Net cash provided by operating activities	100,857	96,061
Cash flows from investing activities:
Purchases of real estate and other assets	(48,685)	(24,857)
Normal capital improvements	(16,499)	(15,033)
Construction capital and other improvements	(3,153)	(3,521)
Renovations to existing real estate assets	(5,150)	(1,417)
Development	(5,034)	(33,232)
Distributions from real estate joint ventures	6	8,865
Proceeds from disposition of real estate assets	52,770	93,127
(Funding) return of escrow for future acquisitions	(6,431)	4,395
Net cash (used in) provided by investing activities	(32,176)	28,327
Cash flows from financing activities:
Net change in credit lines	3,885	(17,936)
Proceeds from notes payable	0	344
Principal payments on notes payable	(17,472)	(17,986)
Payment of deferred financing costs	(172)	(145)
Repurchase of common stock	(937)	(285)
Proceeds from issuances of common shares	8	227
Exercise of stock options	0	1,775
Distributions to noncontrolling interests	(3,223)	(3,086)
Dividends paid on common shares	(57,840)	(54,661)
Net cash used in financing activities	(75,751)	(91,753)
Net (decrease) increase in cash and cash equivalents	(7,070)	32,635
Cash and cash equivalents, beginning of period	25,401	89,333
Cash and cash equivalents, end of period	18,331	121,968
Supplemental disclosure of cash flow information:
Interest paid	27,017	30,408
Supplemental disclosure of noncash investing and financing activities:
Conversion of units to shares of common stock	46	744
Accrued construction in progress	8,392	9,971
Interest capitalized	474	513
Marked-to-market adjustment on derivative instruments	(1,659)	2,300
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	64,677	15,714
Adjustments to reconcile net income to net cash provided by operating activities:
Retail revenue accretion	(29)	(6)
Depreciation and amortization	74,034	91,469
Stock compensation expense	1,289	948
Redeemable stock issued	189	145
Amortization of debt premium	(5,197)	(7,402)
(Gain) loss from investments in real estate joint ventures	(17)	24
Loss on debt extinguishment	2,787	0
Derivative interest (credit) expense	(473)	427
Gain on sale of non-depreciable real estate assets	0	(557)
Gain on sale of depreciable real estate assets excluded from discontinued operations	(30,228)	(2,564)
Gain on sale of discontinued operations	0	(5,481)
Net casualty loss and other settlement proceeds	19	12
Changes in assets and liabilities:
Restricted cash	7,391	787
Other assets	2,441	5,664
Accounts payable	(431)	106
Accrued expenses and other	(16,060)	(3,465)
Security deposits	465	240
Net cash provided by operating activities	100,857	96,061
Cash flows from investing activities:
Purchases of real estate and other assets	(48,685)	(24,857)
Normal capital improvements	(16,499)	(15,033)
Construction capital and other improvements	(3,153)	(3,521)
Renovations to existing real estate assets	(5,150)	(1,417)
Development	(5,034)	(33,232)
Distributions from real estate joint ventures	6	8,865
Proceeds from disposition of real estate assets	52,770	93,127
(Funding) return of escrow for future acquisitions	(6,431)	4,395
Net cash (used in) provided by investing activities	(32,176)	28,327
Cash flows from financing activities:
Net change in credit lines	3,885	(17,936)
Proceeds from notes payable	0	344
Principal payments on notes payable	(17,472)	(17,986)
Payment of deferred financing costs	(172)	(145)
Repurchase of common units	(937)	(285)
Proceeds from issuances of common units	8	227
Exercise of stock options	0	1,775
Distributions paid on common units	(61,063)	(57,747)
Net cash used in financing activities	(75,751)	(91,753)
Net (decrease) increase in cash and cash equivalents	(7,070)	32,635
Cash and cash equivalents, beginning of period	25,401	89,333
Cash and cash equivalents, end of period	18,331	121,968
Supplemental disclosure of cash flow information:
Interest paid	27,017	30,408
Supplemental disclosure of noncash investing and financing activities:
Accrued construction in progress	8,392	9,971
Interest capitalized	474	513
Marked-to-market adjustment on derivative instruments	(1,659)	2,300
Fair value adjustment on debt assumed	0	1,651
Loan assumption	$ 0	$ 31,692