Income Taxes - Reconciliation of Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Beginning Balance	$ 332	$ 287	$ 73
Increases of unrecognized tax benefits taken in prior years			31
Increases of unrecognized tax benefits related to current year			183
Decreases based on tax positions taken during a prior period		(102)
Increases based on tax positions taken during a prior period	3,562
Increases based on tax positions taken during a current period	167	147
Ending Balance	$ 4,061	$ 332	$ 287