Components of Provision for Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components Of Income Tax Expense Benefit [Line Items]
Current, Federal	$ 22,488us-gaap_CurrentFederalTaxExpenseBenefit	$ 20,277us-gaap_CurrentFederalTaxExpenseBenefit	$ 12,128us-gaap_CurrentFederalTaxExpenseBenefit
Current, State	2,952	2,054	971
Current, Foreign	3,195us-gaap_CurrentForeignTaxExpenseBenefit	3,027us-gaap_CurrentForeignTaxExpenseBenefit	2,142us-gaap_CurrentForeignTaxExpenseBenefit
Total current provision	28,635us-gaap_CurrentIncomeTaxExpenseBenefit	25,358us-gaap_CurrentIncomeTaxExpenseBenefit	15,241us-gaap_CurrentIncomeTaxExpenseBenefit
Deferred, Federal	(11,972)	(6,069)	(4,759)
Deferred, State	(1,209)	(634)	(870)
Deferred, Foreign	(715)	(305)	(535)
Total deferred benefit	(13,896)us-gaap_DeferredIncomeTaxExpenseBenefit	(7,008)us-gaap_DeferredIncomeTaxExpenseBenefit	(6,164)us-gaap_DeferredIncomeTaxExpenseBenefit
Total provision	$ 14,739us-gaap_IncomeTaxExpenseBenefit	$ 18,350us-gaap_IncomeTaxExpenseBenefit	$ 9,077us-gaap_IncomeTaxExpenseBenefit

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