Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Income Tax Contingency
PortionOfTaxBenefitRecordedPositionsMoreLikelyThanNotToBeSustained			50.00%
Income Tax Uncertainties [Abstract]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 9,600,000		$ 9,600,000		$ 10,300,000
Unrecognized Tax Benefits, Period Increase (Decrease)	400,000	300,000	(1,100,000)	(2,500,000)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	6,900,000		6,900,000		8,000,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	200,000	200,000
Unrecognized tax benefits, reversal of income tax penalties and interest expense			1,100,000	1,400,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound	600,000		600,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	1,600,000		1,600,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance beginning of period			16,062,000
Additions based on tax positions related to current year			720,000
Additions for tax positions of prior years			698,000
Reductions for tax positions of prior years			(102,000)
Reductions due to lapse of applicable statute of limitations			(2,426,000)
Settlements			0
Balance end of period	14,952,000		14,952,000
Valuation Allowance [Abstract]
Valuation Allowance, Amount	$ 400,000		$ 400,000		$ 1,100,000