Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows from Operating Activities:
Net income	$ 98,743	$ 93,219	$ 225,056
Operating distributions received from unconsolidated joint ventures	1,475	2,338	2,932
Adjustments to reconcile net income to net cash provided by operating activities:
Income attributable to noncontrolling interest- discontinued operations	0	0	453
Depreciation	123,566	113,650	109,730
Amortization of deferred financing costs and fair market value adjustments on notes payable	2,620	2,648	4,777
Settlement of forward starting interest rate swaps	672	0	0
Other amortization	43,939	47,479	56,688
Impairment loss on wholly-owned properties	7,644	0	0
Gain on extinguishment of debt	0	0	(1,041)
Accretion of discount on notes receivable	0	0	(482)
Stock compensation expense	1,590	2,246	4,705
Reduction of long-lived assets due to casualty event	0	1,980	0
Equity in income of unconsolidated joint ventures	3,676	(923)	(1,609)
Loss/(gain) on consolidation	898	0	(1,532)
Gain on sale of real estate assets	(31,292)	(27,577)	(122,657)
Changes in assets and liabilities:
Increase in tenant and straight-line rent receivables, net	(29,101)	(21,720)	(13,295)
(Increase)/decrease in restricted cash and escrows	(60)	8,705	18,720
Increase in prepaid expenses and other assets	(3,427)	(3,837)	(2,727)
(Decrease)/increase in accounts payable and accrued expenses	(6,434)	8,486	3,511
Increase/(decrease) in deferred income	570	(5,769)	(16,134)
Net cash provided by operating activities	215,079	220,925	267,095
Cash Flows from Investing Activities:
Acquisition of real estate assets and related intangibles	(366,182)	(4,225)	(161,576)
Capitalized expenditures, net of accruals	(175,988)	(104,262)	(54,033)
Acquisition of unconsolidated joint ventures, net of cash assumed	(14,242)	0	0
Cash assumed upon consolidation of variable interest entity	0	0	5,063
Net sale proceeds from wholly-owned properties and consolidated joint venture	95,671	93,839	291,785
Net sale proceeds received from unconsolidated joint ventures	0	0	3,036
Investments in unconsolidated joint ventures	(793)	(136)	(151)
Liquidation of noncontrolling interest upon sale of consolidated joint venture	0	0	(95)
Deferred lease costs paid	(34,298)	(48,692)	(47,049)
Net cash provided/(used in) by investing activities	(495,832)	(63,476)	36,980
Cash Flows from Financing Activities:
Deferred financing costs paid	(4,892)	(3,125)	(3,367)
Proceeds from debt	1,085,604	409,000	829,000
Repayments of debt	(500,000)	(465,000)	(822,875)
Net costs of issuance of common stock	(91)	(229)	(252)
Repurchases of common stock as part of announced plan	(173,551)	(88,450)	(3,244)
Dividends paid and discount on dividend reinvestments	(132,301)	(136,378)	(220,365)
Net cash provided by/(used in) financing activities	274,769	(284,182)	(221,103)
Net increase/(decrease) in cash and cash equivalents	(5,984)	(126,733)	82,972
Cash and cash equivalents, beginning of year	12,957	139,690	56,718
Cash and cash equivalents, end of year	$ 6,973	$ 12,957	$ 139,690