Annual report pursuant to Section 13 and 15(d)

Income Taxes - Reconciliation of Income Taxes (Detail)

v2.4.1.9
Income Taxes - Reconciliation of Income Taxes (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Income Tax Disclosure [Abstract]      
U.S. statutory rate, amount $ 8,338us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate $ 4,037us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate $ (1,892)us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate
State income taxes, amount 311us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes 317us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes 783us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes
Qualified Production Activities, amount (21)us-gaap_IncomeTaxReconciliationDeductionsQualifiedProductionActivities    
Other, amount (124)us-gaap_IncomeTaxReconciliationOtherReconcilingItems (51)us-gaap_IncomeTaxReconciliationOtherReconcilingItems (205)us-gaap_IncomeTaxReconciliationOtherReconcilingItems
Income tax expense $ 8,504us-gaap_IncomeTaxExpenseBenefit $ 4,303us-gaap_IncomeTaxExpenseBenefit $ (1,314)us-gaap_IncomeTaxExpenseBenefit
U.S. statutory rate 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
State income taxes 1.00%us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes 2.70%us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes (14.50%)us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes
Qualified Production Activities (0.10%)us-gaap_EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities      
Other (0.20%)us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments (0.40%)us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments 3.80%us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments
Income tax expense 35.70%us-gaap_EffectiveIncomeTaxRateContinuingOperations 37.30%us-gaap_EffectiveIncomeTaxRateContinuingOperations 24.30%us-gaap_EffectiveIncomeTaxRateContinuingOperations