Income Taxes - Significant Components of our Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current Federal, State and Local, Tax Expense (Benefit) [Abstract]
Domestic	$ 0	$ 0	$ 0
Foreign	116	166	0
Total provision for income taxes	$ 116	$ 166	$ 0