Debt - Schedule of Net Carrying Amount of Liability and Equity Components of Notes (Detail) $ in Thousands	Dec. 31, 2019 USD ($)
Liability component:
Principal	$ 690,000
Unamortized debt discount	(106,224)
Unamortized transaction costs	(13,320)
Net carrying amount	570,456
Equity component, net of transaction costs	$ 114,938