Consolidated Statements of Equity (USD $) In Thousands, except Share data	Total USD ($)	Common Stock [Member] USD ($)	Exchangeable Shares [Member]	Series F Preferred Stock [Member]	Series G Preferred Stock [Member]	Additional Paid-in Capital [Member] USD ($)	Retained Earnings [Member] USD ($)	Accumulated Other Comprehensive Income (Loss) [Member] USD ($)	Treasury Stock [Member] USD ($)	Total Stockholders' Equity [Member] USD ($)	Noncontrolling Interest [Member] USD ($)
Balance at Dec. 31, 2011	$ 3,389,263	$ 2				$ 3,216,206	$ 361,527	$ 710	$ (196,493)	$ 3,381,952	$ 7,311
Balance, Shares at Dec. 31, 2011		206,203,005	3,909,110	1
Other comprehensive income (loss)	13,743							13,743		13,743
Acquisitions	37,291					37,291				37,291
Acquisitions, shares		1,927,113
Restricted stock activity	24,845					31,501			(6,656)	24,845
Restricted stock activity, shares		915,816
Stock options exercised	2,385					2,385				2,385
Stock options exercised, shares		224,652
Income tax benefit (expense) from long-term incentive plans	(297)					(297)				(297)
Distributions to non-controlling interests	(17,970)										(17,970)
Net income	322,656						306,629			306,629	16,027
Balance at Dec. 31, 2012	3,771,916	2				3,287,086	668,156	14,453	(203,149)	3,766,548	5,368
Balance, Shares at Dec. 31, 2012		209,270,586	3,909,110	1
Other comprehensive income (loss)	(51,689)							(51,689)		(51,689)
Acquisitions	88,896					88,896				88,896
Acquisitions, shares		3,547,482
Restricted stock activity	23,785					35,876			(12,091)	23,785
Restricted stock activity, shares		(358,753)
Stock options exercised	1,028					1,028				1,028
Stock options exercised, shares		74,342
Exchange of exchangeable shares		409,110	(409,110)
Income tax benefit (expense) from long-term incentive plans	3,699					3,699				3,699
Distributions to non-controlling interests	(17,625)										(17,625)
Net income	421,309						401,921			401,921	19,388
Balance at Dec. 31, 2013	4,241,319	2				3,416,585	1,070,077	(37,236)	(215,240)	4,234,188	7,131
Balance, Shares at Dec. 31, 2013		212,942,767	3,500,000	1
Other comprehensive income (loss)	(86,054)							(86,054)		(86,054)
Acquisitions	134,538					134,538				134,538
Acquisitions, shares		686,382	3,825,971		1
Restricted stock activity	26,690					39,030			(12,340)	26,690
Restricted stock activity, shares		95,475
Stock options exercised	1,179					1,179				1,179
Stock options exercised, shares		91,444
Income tax benefit (expense) from long-term incentive plans	700					700				700
Common stock repurchases	(93,482)								(93,482)	(93,482)
Common stock repurchases, shares		(2,996,278)
Deferral plan shares						874			(874)
Distributions to non-controlling interests	(14,432)										(14,432)
Net income	315,082						296,714			296,714	18,368
Balance at Dec. 31, 2014	$ 4,525,540	$ 2				$ 3,592,906	$ 1,366,791	$ (123,290)	$ (321,936)	$ 4,514,473	$ 11,067
Balance, Shares at Dec. 31, 2014		210,819,790	7,325,971	1	1