XML 89 R41.htm IDEA: XBRL DOCUMENT v2.4.1.9
Income Taxes - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Income Taxes [Line Items]    
Federal statutory rate 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Income tax expense (benefit) $ 22,366us-gaap_IncomeTaxExpenseBenefit $ 18,957us-gaap_IncomeTaxExpenseBenefit
Deferred compensation plan    
Income Taxes [Line Items]    
Income tax expense (benefit) (2,000)us-gaap_IncomeTaxExpenseBenefit
/ us-gaap_TaxCreditCarryforwardAxis
= us-gaap_DeferredCompensationShareBasedPaymentsMember		  
Valuation Allowance, Operating Loss Carryforwards | State    
Income Taxes [Line Items]    
Income tax expense (benefit) $ 5,100us-gaap_IncomeTaxExpenseBenefit
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
/ us-gaap_ValuationAllowancesAndReservesTypeAxis
= us-gaap_ValuationAllowanceOperatingLossCarryforwardsMember