Condensed Consolidated Statements of Changes in Equity (USD $) In Thousands	Total	Common Stock	Contingent Convertible Preferred Stock	Restricted Stock Units	Additional Paid-in Capital	Exchangeable Shares of Subsidiary	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Parent	Noncontrolling Interests
Balance at Dec. 31, 2010		$ 351	$ 46,950	$ 89,365	$ 368,090	$ 6,578	$ 184,621	$ 5,127	$ (330,602)		$ 2,382
Restricted stock units recognized				53,143
Stock issued		7			42,794
Dividends							(55,824)
Net income allocated to noncontrolling interests											6
Exchangeable shares of subsidiary delivered
Currency translation adjustment, net of tax								(1,999)
Repurchased									(65,784)
Restricted stock units delivered				(42,592)
Tax benefit (cost) from the delivery of restricted stock units					1,399
Net income allocated to common stockholders							44,577
Distributions to noncontrolling interests											(1,035)
Balance at Dec. 31, 2011	347,554	358	46,950	99,916	412,283	6,578	173,374	3,128	(396,386)	346,201	1,353
Restricted stock units recognized				27,734
Stock issued		6			44,388
Dividends							(28,007)
Net income allocated to noncontrolling interests
Exchangeable shares of subsidiary delivered						(2,895)
Currency translation adjustment, net of tax	466							466
Repurchased									(19,584)
Restricted stock units delivered				(41,505)
Tax benefit (cost) from the delivery of restricted stock units					(4,495)
Net income allocated to common stockholders	18,376						18,376
Distributions to noncontrolling interests
Balance at Jun. 30, 2012	$ 342,038	$ 364	$ 46,950	$ 86,145	$ 452,176	$ 3,683	$ 163,743	$ 3,594	$ (415,970)	$ 340,685	$ 1,353