Income Taxes - Summary of Tax Effects of Each Item that Give Rise to Deferred Tax Assets (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
Income Tax Disclosure [Abstract]    
Net unrealized gain on securities available for sale $ (2,969) $ (3,615)
Depreciation and amortization (902) (1,293)
Other-than-temporary impairment losses 97 97
Allowance for loan losses 10,349 8,376
Employee benefit and retirement plans 3,687 3,102
Acquisition accounting 2,362 2,581
Other, net 854 462
Net deferred tax asset $ 13,478 $ 9,710