Commitments and Contingencies - Summary of Commitments to Extend Credit and Standby Letters of Credit (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Commitments And Contingencies Disclosure [Abstract]
Commitments to extend credit	$ 271,072	$ 257,195	$ 190,813
Standby letters of credit	$ 7,961	$ 7,665	$ 6,747