Interest Expense on Convertible Senior Notes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument
Contractual interest expense on the coupon	$ 3,009	$ 5,750
Amortization of the discount component and debt issue fees recognized as interest expense	11,019	15,454
Total interest expense on the convertible debt	$ 14,028	$ 21,204