Convertible Notes, Net - Summary of Details about Interest Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Discount and issuance cost amortization	$ 37,403	$ 32,195	$ 28,284
Convertible Senior Note [Member]
Debt Instrument [Line Items]
Cash coupon	28,059	28,059	33,859
Discount and issuance cost amortization	3,319	3,159	5,531
Total interest expense	$ 31,378	$ 31,218	$ 39,390