Summary of Organization - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Organization [Line Items]
Date of entity incorporation				Jun. 23, 1995
Assets	$ 1,117,648			$ 1,117,648		$ 1,093,768
Loans, including Loans held for sale	732,901			732,901		706,634
Deposits	962,099			962,099		892,775
Stockholders' equity	98,434		$ 89,777	98,434	$ 89,777	$ 96,216	$ 85,108
Net income	2,185		1,613	4,214	3,040
Net income applicable to common Stockholders	$ 2,099		$ 1,527	$ 4,043	$ 2,848
Dividends on common stock, per share	$ 0.0375	$ 0.0375	$ 0.0375	$ 0.075	$ 0.075