Commitments and Contingencies - Summary of Commitments to Extend Credit (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Commitments to extend credit	$ 104,978	$ 91,480
Loan commitments [Member]
Loss Contingencies [Line Items]
Commitments to extend credit	104,505	90,946
Standby letters of credit [Member]
Loss Contingencies [Line Items]
Commitments to extend credit	$ 473	$ 534