Condensed Consolidated Statements of Changes in Equity (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	Series H Preferred Stock [Member]	Series I Preferred Stock [Member]	Series J Preferred Stock [Member]	Series K Preferred Stock [Member]	Retained Earnings [Member] USD ($)	Accumulated Other Comprehensive Income (Loss) [Member] USD ($)	Preferred Stock [Member] USD ($)	Common Stock [Member] USD ($)	Additional Paid-in Capital [Member] USD ($)	Parent [Member] USD ($)	Noncontrolling Interest [Member] USD ($)	Total USD ($)
Balance at Dec. 31, 2012					$ (824,008)	$ (66,182)	$ 102	$ 4,078	$ 5,651,170	$ 4,765,160	$ 167,320	$ 4,932,480
Balance (in Shares) at Dec. 31, 2012							102,000	407,782,000
Contributions from noncontrolling interests											858	858
Comprehensive income:
Net income					118,909					118,909	4,871	123,780
Other comprehensive income, net of tax:
Change in unrealized gain on marketable securities						6,228				6,228		6,228
Change in foreign currency translation adjustment						(1,844)				(1,844)	(660)	(2,504)
Redeemable noncontrolling interests											(3,222)	(3,222)
Dividends					(200,971)					(200,971)		(200,971)
Distributions to noncontrolling interests											(5,063)	(5,063)
Issuance of stock								5	9,208	9,213		9,213
Issuance of stock (in Shares)								560,000
Surrender of restricted stock								(2)	(3,174)	(3,176)		(3,176)
Surrender of restricted stock (in Shares)								(212,000)
Exercise of common stock options								15	27,927	27,942		27,942
Exercise of common stock options (in Shares)								1,487,000
Acquisition of noncontrolling interests									(5,430)	(5,430)	(20,096)	(25,526)
Amortization of equity awards									6,242	6,242		6,242
Balance at Jun. 30, 2013					(906,070)	(61,798)	102	4,096	5,685,943	4,722,273	144,008	4,866,281
Balance (in Shares) at Jun. 30, 2013							102,000	409,617,000
Balance at Dec. 31, 2013					(996,058)	(64,982)	102	4,097	5,689,258	4,632,417	137,109	4,769,526
Balance (in Shares) at Dec. 31, 2013							102,000	409,731,000
Contributions from noncontrolling interests											2,313	2,313
Comprehensive income:
Net income					176,512					176,512	11,298	187,810
Other comprehensive income, net of tax:
Change in unrealized gain on marketable securities						8,111				8,111		8,111
Change in foreign currency translation adjustment						(2,721)				(2,721)	(175)	(2,896)
Redeemable noncontrolling interests											(3,224)	(3,224)
Dividends					(213,989)					(213,989)		(213,989)
Distributions to noncontrolling interests											(24,464)	(24,464)
Issuance of stock								7	11,444	11,451		11,451
Issuance of stock (in Shares)								697,000
Surrender of restricted stock								(2)	(3,727)	(3,729)		(3,729)
Surrender of restricted stock (in Shares)								(175,000)
Exercise of common stock options								8	12,328	12,336		12,336
Exercise of common stock options (in Shares)								766,000
Acquisition of noncontrolling interests									(53)	(53)	(766)	(819)
Amortization of equity awards									6,293	6,293		6,293
Balance at Jun. 30, 2014					$ (1,033,535)	$ (59,592)	$ 102	$ 4,110	$ 5,715,543	$ 4,626,628	$ 122,091	$ 4,748,719
Balance (in Shares) at Jun. 30, 2014	70,000	16,000	9,000	7,000			102,000	411,019,000