Income Taxes (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Income Tax Contingency
PortionOfTaxBenefitRecordedPositionsMoreLikelyThanNotToBeSustained	50.00%
Income Tax Uncertainties [Abstract]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 9,500,000		$ 10,100,000
Unrecognized Tax Benefits, Period Increase (Decrease)	(600,000)	(900,000)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	7,000,000		7,400,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	(400,000)	(800,000)
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	15,723,000
Additions based on tax positions related to current year	208,000
Additions for tax positions of prior years	616,000
Reductions for tax positions of prior years	(185,000)
Reductions due to lapse of applicable statute of limitations	(1,257,000)
Settlements	0
Balance end of period	15,105,000
Valuation Allowance [Abstract]
Valuation Allowance, Amount	$ 400,000