Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Payroll and payroll-related expenses	$ 22,772	$ 21,204
Sales and marketing accruals	6,220	8,221
Accrued revenue allowances	140,863	93,815
All other	28,786	16,586
Accrued expenses and other current liabilities	$ 198,641	$ 139,826