Other Real Estate Owned - Schedule for Changes in Other Real Estate Owned (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Real Estate [Abstract]
Beginning of year	$ 5,811	$ 4,754
Transfers in	3,006	3,164
Acquired in acquisition	2,744	115
Gain on sales	156	131	$ 505
Proceeds from sales	(3,017)	(2,266)	(4,368)
Other real estate	8,700	5,898
Additions to valuation reserve	(44)	(87)
Recorded investment	$ 8,656	$ 5,811	$ 4,754