Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

Income Taxes - Components of Income Tax Expense Benefit (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current:
Federal									$ 9,512us-gaap_CurrentFederalTaxExpenseBenefit	$ 9,039us-gaap_CurrentFederalTaxExpenseBenefit	$ 8,893us-gaap_CurrentFederalTaxExpenseBenefit
State									996	1,324	1,385
Total current									10,508us-gaap_CurrentIncomeTaxExpenseBenefit	10,363us-gaap_CurrentIncomeTaxExpenseBenefit	10,278us-gaap_CurrentIncomeTaxExpenseBenefit
Deferred:
Federal									30	(1,421)	664
State									73	(329)	(15)
Total deferred									103us-gaap_DeferredIncomeTaxExpenseBenefit	(1,750)us-gaap_DeferredIncomeTaxExpenseBenefit	649us-gaap_DeferredIncomeTaxExpenseBenefit
Income tax expense (benefit)	$ 2,491us-gaap_IncomeTaxExpenseBenefit	$ 2,790us-gaap_IncomeTaxExpenseBenefit	$ 2,767us-gaap_IncomeTaxExpenseBenefit	$ 2,563us-gaap_IncomeTaxExpenseBenefit	$ 784us-gaap_IncomeTaxExpenseBenefit	$ 2,658us-gaap_IncomeTaxExpenseBenefit	$ 2,774us-gaap_IncomeTaxExpenseBenefit	$ 2,397us-gaap_IncomeTaxExpenseBenefit	$ 10,611us-gaap_IncomeTaxExpenseBenefit	$ 8,613us-gaap_IncomeTaxExpenseBenefit	$ 10,927us-gaap_IncomeTaxExpenseBenefit