Quarterly report pursuant to Section 13 or 15(d)

Accounting for Uncertainty in Income Taxes - Additional Information (Detail)

v2.4.1.9
Accounting for Uncertainty in Income Taxes - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Mar. 31, 2014
Income Tax Disclosure [Abstract]      
Liability for unrecognized tax $ 8.2us-gaap_UnrecognizedTaxBenefits   $ 12.4us-gaap_UnrecognizedTaxBenefits
Unrecognized tax favorable impact on effective tax rate 3.6us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate   5.6us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
Accrued interest and penalties applied to uncertain tax positions $ 3.4us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense $ 3.3us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense