Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flow from operating activities:
Net income	$ 241,353	$ 280,275	$ 182,090
Depreciation and amortization	257,855	262,742	251,139
Impairment charges	190,218	59,569	32,763
Gain on sale of development properties			(12,074)
Gain on sale of operating properties	(51,529)	(94,369)	(17,435)
Equity in income of joint ventures, net	(208,689)	(112,896)	(63,467)
Gain on change in control of interests, net	(21,711)	(15,555)	(569)
Equity in income from other real estate investments, net	(31,136)	(53,397)	(51,813)
Distributions from joint ventures and other real estate investments	258,050	194,110	163,048
Change in accounts and notes receivable	7,213	2,940	(19,271)
Change in accounts payable and accrued expenses	10,166	(11,281)	(8,082)
Change in other operating assets and liabilities	(81,755)	(33,084)	(7,716)
Net cash flow provided by operating activities	570,035	479,054	448,613
Cash flow from investing activities:
Acquisition of operating real estate	(354,287)	(442,541)	(268,282)
Improvements to operating real estate	(107,277)	(109,928)	(75,017)
Improvements to real estate under development	(591)	(2,487)	(37,896)
Investment in marketable securities	(33,588)
Proceeds from sale/repayments of marketable securities	26,406	156	188,003
Investments and advances to real estate joint ventures	(296,550)	(219,885)	(171,695)
Reimbursements of investments and advances to real estate joint ventures	440,161	187,856	63,529
Investment in other real estate investments	(23,566)	(5,638)	(6,958)
Reimbursements of investments and advances to other real estate investments	30,151	33,720	68,881
Investment in mortgage loans receivable	(11,469)	(16,021)
Collection of mortgage loans receivable	29,192	63,600	19,148
Investment in other investments	(21,366)	(924)	(730)
Reimbursements of other investments	9,175	11,553	20,116
Proceeds from sale of operating properties	385,844	449,539	135,646
Proceeds from sale of development properties			44,495
Net cash flow provided by/(used for) investing activities	72,235	(51,000)	(20,760)
Cash flow from financing activities:
Principal payments on debt, excluding normal amortization of rental property debt	(256,346)	(284,815)	(62,470)
Principal payments on rental property debt	(23,804)	(23,130)	(22,720)
Principal payments on construction loan financings		(2,177)	(3,428)
Proceeds from mortgage/construction loan financings	35,974	14,776	20,346
(Repayments)/Proceeds under unsecured revolving credit facility, net	(57,775)	8,559	112,137
Proceeds from issuance of unsecured term loan/notes	621,562	400,000
Repayments under unsecured term loan/notes	(546,717)	(215,900)	(92,600)
Financing origination costs	(8,041)	(2,138)	(11,478)
Redemption of noncontrolling interests	(30,086)	(42,315)	(26,682)
Dividends paid	(400,354)	(382,722)	(353,764)
Proceeds from issuance of stock	30,210	796,748	6,537
Redemption of preferred stock		(635,000)
Repurchase of common stock		(30,947)	(6,003)
Net cash flow used for financing activities	(635,377)	(399,061)	(440,125)
Change in cash and cash equivalents	6,893	28,993	(12,272)
Cash and cash equivalents, beginning of year	141,875	112,882	125,154
Cash and cash equivalents, end of year	148,768	141,875	112,882
Interest paid during the year (net of capitalized interest of $1,263, $1,538 and $7,086, respectively)	216,258	226,775	220,270
Income taxes paid during the year	$ 33,838	$ 2,122	$ 2,606