Income Taxes (Details) (USD $)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Jun. 30, 2011	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Income Tax Contingency [Line Items]
PortionOfTaxBenefitRecordedPositionsMoreLikelyThanNotToBeSustained			50.00%
Income Tax Uncertainties [Abstract]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 10,100,000			$ 10,100,000		$ 11,700,000
Unrecognized Tax Benefits, Period Increase (Decrease)	300,000	300,000		(2,500,000)	(2,900,000)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	7,800,000			7,800,000		9,200,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	(200,000)	(200,000)		1,400,000	1,600,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound	300,000			300,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	1,300,000			1,300,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance beginning of period			18,140,000	18,140,000
Additions based on tax positions related to current year				831,000
Additions for tax positions of prior years				0
Reductions for tax positions of prior years				(15,000)
Reductions due to lapse of applicable statute of limitations				(3,278,000)
Settlements				0
Balance end of period	15,678,000			15,678,000
Valuation Allowance [Abstract]
Valuation Allowance, Amount			$ 1,100,000