Summary of Change in Reserves for Discounts and Allowances (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	$ 70,466	$ 50,970
Provision	123,948	80,871
Payments/credits	(107,165)	(64,156)
Ending balance	87,249	67,685
Chargebacks [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	799	2,281
Provision	8,756	9,350
Payments/credits	(9,193)	(10,878)
Ending balance	362	753
Rebates [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	60,506	41,771
Provision	76,845	54,686
Payments/credits	(70,645)	(37,818)
Ending balance	66,706	58,639
Prompt Pay [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	2,798	1,949
Provision	9,508	6,603
Payments/credits	(8,930)	(5,865)
Ending balance	3,376	2,687
Other Accruals [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance	6,363	4,969
Provision	28,839	10,232
Payments/credits	(18,397)	(9,595)
Ending balance	$ 16,805	$ 5,606