Income Taxes - Schedule of Gross Unrecognized Tax Benefits (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Interest and penalties	$ 13,083	$ 13,004	$ 12,200	$ 14,799