Summary of Total Reserves Included in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Receivables Net Current [Abstract]
Reduction to accounts receivable	$ 7,020	$ 6,254
Component of accrued expenses	44,798	45,249
Total reserves	$ 51,818	$ 51,503	$ 40,506	$ 28,510