Income Taxes Unrecognized tax benefits (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Jan. 02, 2010
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits	$ 37,586	$ 91,349		$ 78,811
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	0	15,998
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions	0	(260)
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	(17,362)	(3,200)
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities	(36,401)	0
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	3,891	16,802
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	5,373	10,774
Unrecognized Tax Benefits, Interest on Income Taxes Expense	(3,096)	2,436	2,409
2008 [Member] | CANADA
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority		4,560
2006 [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	6,404
2006 [Member] | UNITED STATES
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Interest Paid	1,633
2007 [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	4,361
2007 [Member] | UNITED STATES
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Interest Paid	$ 673