Income Taxes - Income Tax Provision (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current provision (benefit) for:
Federal income taxes	$ (1)	$ (36)	$ 153
State income taxes	(8)	11	17
Total current provision (benefit)	$ (9)	$ (25)	$ 170