Convertible Senior Notes - Schedule of Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
0.375% Convertible Senior Notes Due 2025 [Member]
Debt Instrument [Line Items]
Contractual interest expense	$ 431	$ 431	$ 1,291	$ 1,294
Amortization of debt discount		4,573		13,474
Amortization of issuance costs	492	359	1,465	1,059
Total interest expense	$ 923	5,363	2,756	15,827
0.25% Convertible Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Contractual interest expense		26	20	142
Amortization of debt discount		623		3,333
Amortization of issuance costs		47	44	249
Total interest expense		$ 696	$ 64	$ 3,724