Premises and Equipment - Summary of Premises and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Property, Plant and Equipment, Net, by Type [Abstract]
Land & land improvements	$ 5,953	$ 5,975
Buildings	30,147	30,103
Furniture and equipment	28,547	27,881
Premises and equipment, gross	64,647	63,959
Less: Accumulated depreciation	(32,466)	(32,397)
Premises and equipment less depreciation, gross	32,181	31,562
Construction in progress		50
Total premises and equipment	$ 32,181	$ 31,612