Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Contingency
PortionOfTaxBenefitRecordedPositionsMoreLikelyThanNotToBeSustained	50.00%
Income Tax Uncertainties [Abstract]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 10,300,000	$ 11,700,000
Unrecognized Tax Benefits, Period Increase (Decrease)	(2,100,000)	(2,600,000)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	8,000,000	9,200,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	1,200,000	1,400,000	1,700,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound	200,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	1,200,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance beginning of period	18,140,000
Additions based on tax positions related to current year	1,200,000
Additions for tax positions of prior years	0
Reductions for tax positions of prior years	0
Reductions due to lapse of applicable statute of limitations	(3,278,000)
Settlements	0
Balance end of period	16,062,000	18,140,000
Valuation Allowance [Abstract]
Valuation Allowance, Amount	$ 1,100,000