Income Tax - Components of Income Tax Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Tax Disclosure [Abstract]
Current tax provision	$ 2,309	$ 964	$ 4,355	$ 4,553
Deferred tax (benefit) provision	(189)	998	11	(430)
Income tax expense	$ 2,120	$ 1,962	$ 4,366	$ 4,123