Accounting for Income Taxes - Additional Information (Details) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Income Taxes [Line Items]
Provision for income taxes	$ 11,295,000us-gaap_IncomeTaxExpenseBenefit	$ 9,961,000us-gaap_IncomeTaxExpenseBenefit
Effective income tax rate, continuing operations	23.80%	23.50%
Statutory rate	35.00%
Valuation allowance, deferred tax asset	32,700,000
Unrecognized tax benefits	34,400,000us-gaap_UnrecognizedTaxBenefits
Tax holiday effect on diluted earnings per share	$ 0.10	$ 0.09
Foreign Tax Authority [Member]
Income Taxes [Line Items]
Foreign income tax rate	30.00%
Tax Holiday effect	$ 8,200,000	$ 7,600,000

Effective Income Tax Rate Reconciliation, Tax Holiday, Effect on Diluted Earnings Per Share

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Effective Income Tax Reconciliation, at Foreign Income Tax Rate

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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-Glossary Income Tax Expense (or Benefit)

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to income exempt from income tax because of a tax holiday.

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

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