Income Taxes (Details 4) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance, beginning of year	$ 29,533,000us-gaap_UnrecognizedTaxBenefits	$ 35,143,000us-gaap_UnrecognizedTaxBenefits	$ 29,200,000us-gaap_UnrecognizedTaxBenefits
Increases related to current year tax positions	1,457,000	979,000	7,220,000
Increases related to prior year tax positions	569,000	714,000	1,559,000
Decreases related to prior year tax positions	(781,000)	(2,736,000)	(343,000)
Lapse of statute of limitations	(5,165,000)	(2,012,000)	(1,887,000)
Settlements	(9,655,000)	(2,555,000)	(606,000)
Balance, end of year	15,401,000us-gaap_UnrecognizedTaxBenefits	29,533,000us-gaap_UnrecognizedTaxBenefits	35,143,000us-gaap_UnrecognizedTaxBenefits
Accrued interest and penalties	$ 1,200,000

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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