Income Taxes - Summary of the Change in the Net Deferred Tax Asset (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Income Tax Disclosure [Abstract]      
Balance at beginning of year $ 9,710 $ 7,434 $ 5,441
Deferred income tax (benefit) provision (3,224) (2,781) 611
Deferred tax effects of:      
Change in net unrealized gain (loss) on securities available for sale 646 (489) 2,511
Amortization of defined benefit plan net actuarial loss and prior service cost (102) (16) 93
Balance at end of year $ 13,478 $ 9,710 $ 7,434