Transactions with Executive Officers, Directors, and Principal Shareholders - Schedule of Activity Relating to Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance – January 1	$ 9	$ 7,273	$ 3,272
Additions	2,218	5	9,280
Repayments	(2,007)	(7,269)	(5,279)
Balance – December 31	$ 220	$ 9	$ 7,273