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	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Ending Balance	$ 7,618	$ 7,378
Transfers into (out of) Level 3		1,944
Change Included in Earnings	(701)	(1,301)
Issuances	941	570
Beginning Balance	$ 7,378	$ 6,165