Schedule of Estimated Accrued Rebates and Reserve for Cash Discounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accrued rebates
Supplemental Balance Sheet Information [Line Items]
Balance at Beginning of Period	$ 43,116	$ 36,472	$ 34,737
Provision for Current Period Sales	91,748	67,843	52,596
Payments	(77,701)	(61,199)	(50,861)
Balance at End of Period	57,163	43,116	36,472
Reserve for cash discounts
Supplemental Balance Sheet Information [Line Items]
Balance at Beginning of Period	1,197	1,055	888
Provision for Current Period Sales	15,335	12,474	10,672
Payments	(14,643)	(12,332)	(10,505)
Balance at End of Period	$ 1,889	$ 1,197	$ 1,055