Convertible Notes, Net - Summary of Details about Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Instrument [Line Items]
Discount and issuance cost amortization			$ 29,698	$ 28,122
Convertible Senior Note [Member]
Debt Instrument [Line Items]
Cash coupon	$ 7,015	$ 7,015	21,045	21,045
Discount and issuance cost amortization	873	831	2,595	2,470
Total interest expense	$ 7,888	$ 7,846	$ 23,640	$ 23,515

Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

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