Fair Value Measurement - Reconciliation of Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3) on Recurring Basis (Detail) - Mortgage Servicing Rights [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 7,140	$ 7,057	$ 7,618	$ 7,378
Issuances	281	236	501	421
Change included in earnings	(701)	521	(1,399)	15
Balance at end of period	$ 6,720	$ 7,814	$ 6,720	$ 7,814