Income Taxes - Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current
U.S.	$ 0	$ 0	$ 0
State	0	0	0
Foreign	13	6	6
Total current income tax expense	13	6	6
Deferred
U.S.		(218)	(5,863)
State		(36)	691
Foreign	(39)	326	6
Total deferred income tax expense (benefit)	(39)	72	(5,166)
Total income tax expense (benefit)	$ (26)	$ 78	$ (5,160)