Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Consolidated net income	$ 22,005	$ 25,068
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, Amortization and Accretion, Net	(10)	0
Depreciation and amortization	34,237	31,549
Stock compensation expense	630	814
Redeemable stock issued	159	116
Amortization of debt premium	225	(90)
Loss from investments in real estate joint ventures	(54)	31
Gain on debt extinguishment	169	(20)
Derivative interest expense	267	164
Gain on sale of discontinued operations	0	(9,429)
Net casualty loss and other settlement proceeds	(16)	58
Changes in assets and liabilities:
Restricted cash	159	207
Other assets	(3,466)	2,445
Accounts payable	1,086	1,910
Accrued expenses and other	(12,985)	(14,994)
Security deposits	161	82
Net cash provided by operating activities	42,117	37,911
Cash flows from investing activities:
Purchases of real estate and other assets	(32,561)	0
Improvements to existing real estate assets	(8,701)	(11,426)
Construction capital and other improvements	(576)	(795)
Renovations to Existing Real Estate Assets	2,187	2,934
Development	(12,240)	(26,745)
Distributions from real estate joint ventures	4,964	459
Contributions to real estate joint ventures	(16)	(51)
Proceeds from disposition of real estate assets	76	28,964
Funding of escrow for future acquisitions	0	(21,585)
Net cash used in investing activities	(51,241)	(34,113)
Cash flows from financing activities:
Net change in credit lines	19,000	(158,802)
Proceeds from notes payable	0	50,000
Principal payments on notes payable	(1,370)	(807)
Payment of deferred financing costs	(120)	(1,397)
Repurchase of common stock	(673)	(1,415)
Proceeds from issuances of common shares	22,058	120,135
Distributions to noncontrolling interests	(1,204)	(1,280)
Dividends paid on common shares	(29,418)	(25,723)
Net cash (used in) provided by financing activities	8,273	(19,289)
Net (decrease) increase in cash and cash equivalents	(851)	(15,491)
Cash and cash equivalents, beginning of period	9,075	57,317
Cash and cash equivalents, end of period	8,224	41,826
Supplemental disclosure of cash flow information:
Interest paid	16,400	16,911
Supplemental disclosure of noncash investing and financing activities:
Conversion of units to shares of common stock	443	28
Accrued construction in progress	7,126	10,027
Interest capitalized	448	638
Marked-to-market adjustment on derivative instruments	$ 4,096	$ 4,084