Loans - Schedule of Modified TDRs (Detail) - Troubled Debt Restructurings - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Financing Receivable, Modifications
Extended maturities	$ 7,199	$ 3,061
Maturity and interest rate adjustment	3,224	253
Movement to or extension of interest-rate only payments	1,290	0
Forbearance	1,220	5,296
Other concession(s)	232	36,172
Total	13,165	44,782
Total TDRs	13,200	44,800
TDRs in accrual status	11,800	39,600
TDRs in non-accrual status	$ 1,400	$ 5,200