Premises and Equipment - Summary of Premises and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment, Net, by Type [Abstract]
Land & land improvements	$ 10,785	$ 8,909
Buildings	45,868	38,643
Furniture and equipment	32,972	31,081
Premises and equipment, gross	89,625	78,633
Less: Accumulated depreciation	(38,606)	(35,518)
Premises and equipment less depreciation, gross	51,019	43,115
Construction in progress	709	696
Total premises and equipment	$ 51,728	$ 43,811