Consolidated Statements of Changes in Equity (USD $) In Thousands, except Share data, unless otherwise specified	Series of Individually Immaterial Business Acquisitions [Member] Additional Paid-in Capital [Member] USD ($)	Series of Individually Immaterial Business Acquisitions [Member] Parent [Member] USD ($)	Series of Individually Immaterial Business Acquisitions [Member] Noncontrolling Interest [Member] USD ($)	Series of Individually Immaterial Business Acquisitions [Member] USD ($)	Contributions [Member] Noncontrolling Interest [Member] USD ($)	Contributions [Member] USD ($)	Redeemable Noncontrolling Interests [Member] Noncontrolling Interest [Member] USD ($)	Redeemable Noncontrolling Interests [Member] USD ($)	Retained Earnings [Member] Series H Preferred Stock [Member] USD ($)	Retained Earnings [Member] USD ($)	Accumulated Other Comprehensive Income (Loss) [Member] USD ($)	Preferred Stock [Member] USD ($)	Preferred Stock [Member] USD ($)	Common Stock [Member] USD ($)	Common Stock [Member] USD ($)	Additional Paid-in Capital [Member] Common Stock [Member] USD ($)	Additional Paid-in Capital [Member] Preferred Stock [Member] USD ($)	Additional Paid-in Capital [Member] USD ($)	Parent [Member] Series H Preferred Stock [Member] USD ($)	Parent [Member] Common Stock [Member] USD ($)	Parent [Member] Preferred Stock [Member] USD ($)	Parent [Member] USD ($)	Noncontrolling Interest [Member] USD ($)	Series H Preferred Stock [Member] USD ($)	Series F Preferred Stock [Member]	Series G Preferred Stock [Member]	Series I Preferred Stock [Member]	Series J Preferred Stock [Member]	Series K Preferred Stock [Member]	Common Stock [Member] USD ($)	Preferred Stock [Member] USD ($)	Total USD ($)
Balance at Dec. 31, 2010										$ (515,164)	$ (23,853)		$ 954		$ 4,064			$ 5,469,841				$ 4,935,842	$ 225,444									$ 5,161,286
Balance (in Shares) at Dec. 31, 2010													954,000		406,424,000
Contributions from noncontrolling interests																							1,045									1,045
Comprehensive income:
Net income										169,051												169,051	13,039									182,090
Other comprehensive income, net of tax:
Change in unrealized gain on marketable securities											(4,065)											(4,065)										(4,065)
Change in unrealized gain on interest rate swaps											549											549										549
Change in foreign currency translation adjustment											(80,291)											(80,291)	(1,937)									(82,228)
Redeemable noncontrolling interests																							(6,370)									(6,370)
Dividends ($0.73 per Common Share; $1.6625 per
Dividends									(356,886)										(356,886)					(356,886)
Distributions to noncontrolling interests																							(13,827)									(13,827)
Issuance of stock															5			4,936				4,941										4,941
Issuance of stock (in Shares)															438,000
Surrender of common stock															(2)			(579)				(581)										(581)
Surrender of common stock (in Shares)															(34,000)
Repurchase of common stock															(2)			(6,001)				(6,003)										(6,003)
Repurchase of common stock (in Shares)															(334,000)																	(333,998)
Exercise of common stock options															4			6,533				6,537										6,537
Exercise of common stock options (in Shares)															444,000																	444,368
Acquisition of noncontrolling interests	4,452	4,452	(23,637)	(19,185)
Amortization of equity awards																		12,840				12,840										12,840
Balance at Dec. 31, 2011										(702,999)	(107,660)		954		4,069			5,492,022				4,686,386	193,757									4,880,143
Balance (in Shares) at Dec. 31, 2011													954,000		406,938,000
Contributions from noncontrolling interests					1,384	1,384
Comprehensive income:
Net income										266,073												266,073	14,202									280,275
Other comprehensive income, net of tax:
Change in unrealized gain on marketable securities											3,013											3,013										3,013
Change in unrealized gain on interest rate swaps											450											450										450
Change in foreign currency translation adjustment											38,015											38,015	5,500									43,515
Redeemable noncontrolling interests																																(13,998)
Dividends ($0.73 per Common Share; $1.6625 per
Dividends										(387,082)												(387,082)										(387,082)
Distributions to noncontrolling interests																							(15,328)									(15,328)
Issuance of stock												32		11		18,104	774,125			18,115	774,157									18,115	774,157
Issuance of stock (in Shares)												32,000		1,096,000
Surrender of common stock															(1)			(2,072)				(2,073)										(2,073)
Surrender of common stock (in Shares)															(111,000)
Repurchase of common stock															(16)			(30,931)				(30,947)										(30,947)
Repurchase of common stock (in Shares)															(1,636,000)																	(1,635,823)
Exercise of common stock options															15			22,576				22,591										22,591
Exercise of common stock options (in Shares)															1,495,000																	1,495,432
Acquisition of noncontrolling interests	(95)	(95)	(25,858)	(25,953)			(6,337)	(6,337)
Amortization of equity awards																		11,557				11,557										11,557
Redemption of preferred stock													(884)					(634,116)				(635,000)										(635,000)
Redemption of preferred stock (in Shares)													(884,000)
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																							1,026									1,026
Comprehensive income:
Net income										236,281												236,281	5,072									241,353
Other comprehensive income, net of tax:
Change in unrealized gain on marketable securities											6,773											6,773										6,773
Change in foreign currency translation adjustment											(5,573)											(5,573)	1,365									(4,208)
Redeemable noncontrolling interests																							(6,892)									(6,892)
Dividends ($0.73 per Common Share; $1.6625 per
Dividends										(408,331)												(408,331)										(408,331)
Distributions to noncontrolling interests																							(10,686)									(10,686)
Issuance of stock														5		9,208				9,213										9,213
Issuance of stock (in Shares)														560,000
Surrender of common stock															(2)			(3,889)				(3,891)										(3,891)
Surrender of common stock (in Shares)															(247,000)
Repurchase of common stock (in Shares)																																0
Exercise of common stock options															16			30,193				30,209										30,209
Exercise of common stock options (in Shares)															1,636,000																	1,636,300
Acquisition of noncontrolling interests	(8,894)	(8,894)	(20,096)	(28,990)
Amortization of equity awards																		11,470				11,470										11,470
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									70,000			16,000	9,000	7,000