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, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Tax Disclosure [Abstract]
Provision (benefit) for income taxes at statutory rate	$ 789	$ (1,565)	$ 1,530	$ (4,409)
Tax effect of:
Tax-exempt investment income	(5)	(1)	(10)	(2)
Change in the beginning of the period balance of the valuation allowance for deferred tax assets allocated to federal income taxes	(749)	1,545	(1,635)	4,372
Restricted stock		1	171	13
State income taxes, net of federal income tax benefit and valuation allowance	147	(262)	214	(183)
Other	6	20	11	26
Income tax expense (benefit)	$ 188	$ (262)	$ 281	$ (183)