Loan Servicing Rights - Components of Loan Servicing Rights and Valuation Allowance (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Transfers and Servicing [Abstract]
Beginning balance	$ 9,584
Additions	2,553	$ 9,066
Amortization	(1,804)	(278)
Ending balance	10,333	8,788
Valuation allowance:
Beginning balance	(50)
(Additions)/recoveries	0	0
Ending balance	(50)
Loan servicing rights, net	$ 10,283	$ 8,788	$ 9,500