Segment Information (Details 1) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Segment Income Loss From Continuing Operations Before Provision For Income Tax [Line Items]
Income Loss From Continuing Operations Before Provision For Income Tax Segment	$ 200,406	$ 198,072	$ 442,255	$ 391,387
US Segment Reporting Information Member
Segment Income Loss From Continuing Operations Before Provision For Income Tax [Line Items]
Income Loss From Continuing Operations Before Provision For Income Tax Segment	116,171	120,775	267,068	252,347
Canada Segment Reporting Information Member
Segment Income Loss From Continuing Operations Before Provision For Income Tax [Line Items]
Income Loss From Continuing Operations Before Provision For Income Tax Segment	43,992	33,748	74,663	52,721
Europe And South Africa Segment Reporting Information Member
Segment Income Loss From Continuing Operations Before Provision For Income Tax [Line Items]
Income Loss From Continuing Operations Before Provision For Income Tax Segment	16,241	22,326	42,560	32,983
Asia Pacific Segment Reporting Information Member
Segment Income Loss From Continuing Operations Before Provision For Income Tax [Line Items]
Income Loss From Continuing Operations Before Provision For Income Tax Segment	7,914	23,761	33,242	50,206
Corporate And Other Segment Reporting Information Member
Segment Income Loss From Continuing Operations Before Provision For Income Tax [Line Items]
Income Loss From Continuing Operations Before Provision For Income Tax Segment	$ 16,088	$ (2,538)	$ 24,722	$ 3,130