Income Taxes - Unrecognized Tax Benefits Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Interest on Income Taxes Expense	$ 2,068	$ (1,599)	$ 4,678
Unrecognized Tax Benefits	63,498	66,110	68,833
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions	10,850	14,067
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions	(2,389)	(20,273)
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	7,602	5,835
Unrecognized Tax Benefits, Decreases Resulting from Current Period Tax Positions	0	0
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities	(12,879)	(65)
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	(5,796)	(2,287)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 13,411	$ 12,348