Income Taxes - Provision (Benefit) for Income Taxes Differs from Amounts Computed by Applying Statutory Federal Corporate Tax Rate (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Tax Disclosure [Abstract]
Provision for income taxes at statutory rate	$ 1,303	$ 789	$ 1,495	$ 1,530
Tax effect of:
Tax-exempt investment income	(5)	(5)	(10)	(10)
Change in the beginning of the period balance of the valuation allowance for deferred tax assets allocated to federal income taxes	(1,233)	(749)	(1,456)	(1,635)
Stock-based compensation	7		44	171
State income taxes, net of federal income tax benefit and valuation allowance	175	147	201	214
Other	7	6	16	11
Income tax expense	$ 254	$ 188	$ 290	$ 281