Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flow from operating activities:
Net income	$ 187,810	$ 123,780
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	129,296	127,042
Impairment charges	99,952	81,546
Gain on sale of operating properties	(30,907)	(5,446)
Equity in income of joint ventures, net	(98,286)	(83,616)
Gains on change in control of interests	(69,342)	(21,711)
Equity in income from other real estate investments, net	(10,367)	(19,363)
Distributions from joint ventures and other real estate investments	125,694	82,245
Change in accounts and notes receivable	2,178	11,142
Change in accounts payable and accrued expenses	(1,294)	6,755
Change in other operating assets and liabilities	(8,637)	(36,846)
Net cash flow provided by operating activities	326,097	265,528
Cash flow from investing activities:
Acquisition of operating real estate	(362,160)	(145,303)
Improvements to operating real estate	(52,875)	(49,497)
Improvements to real estate under development	(107)	(326)
Investment in marketable securities	(4,556)	(33,588)
Proceeds from sale/repayments of marketable securities	219	10,758
Investments and advances to real estate joint ventures	(46,644)	(239,903)
Reimbursements of investments and advances to real estate joint ventures	113,757	295,186
Investment in other real estate investments	(1,372)	(23,227)
Reimbursements of investments and advances to other real estate investments	12,907	1,200
Investment in mortgage loans receivable		(11,017)
Collection of mortgage loans receivable	7,115	8,779
Investment in other investments		(21,366)
Reimbursements of other investments		463
Proceeds from sale of operating properties	161,737	110,389
Net cash flow used for investing activities	(171,979)	(97,452)
Cash flow from financing activities:
Principal payments on debt, excluding normal amortization of rental property debt	(233,800)	(66,206)
Principal payments on rental property debt	(11,060)	(12,094)
Proceeds from mortgage loan financings		17,374
Proceeds/(repayments) under unsecured revolving credit facility, net	143,060	(62,966)
Proceeds from issuance of unsecured term loan/notes	500,000	428,118
Repayments under unsecured term loan/notes	(294,570)	(253,225)
Financing origination costs	(11,911)	(6,096)
Redemption of/distributions to noncontrolling interests, net	(1,059)	(27,184)
Dividends paid	(213,699)	(199,164)
Proceeds from issuance of stock	12,336	27,942
Net cash flow used for financing activities	(110,703)	(153,501)
Change in cash and cash equivalents	43,415	14,575
Cash and cash equivalents, beginning of period	148,768	141,875
Cash and cash equivalents, end of period	192,183	156,450
Interest paid during the period (net of capitalized interest of $737 and $579, respectively)	102,478	108,906
Income taxes paid during the period	$ 10,465	$ 798