Income Taxes - Expense (Benefit) for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income (loss) before expense (benefit) for income taxes	$ 2,954		$ (9,995)		$ (29,663)	$ (44,778)
Expense (benefit) for income taxes	82,964		(4,875)		63,938	(6,795)
Net loss	$ (80,010)	$ (13,591)	$ (5,120)	$ (32,863)	$ (93,601)	$ (37,983)