Product Revenues, Net, Accounts Receivable, Net, and Reserves for Product Revenues - Summary of Change in Reserves for Discounts and Allowances (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	$ 194,299	$ 164,772
Provision	165,694	79,763
Adjustments relating to prior periods	(6,041)	(1,749)
Payments/credits	(118,376)	(86,886)
Ending Balance	235,576	155,900
Chargebacks [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	45,904	27,486
Provision	73,443	20,466
Adjustments relating to prior periods	0	783
Payments/credits	(52,480)	(30,358)
Ending Balance	66,867	18,377
Rebates [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	107,843	98,194
Provision	58,798	35,951
Adjustments relating to prior periods	(5,416)	(2,532)
Payments/credits	(44,155)	(36,623)
Ending Balance	117,070	94,990
Prompt Pay [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	5,941	3,831
Provision	5,552	4,381
Adjustments relating to prior periods	0	0
Payments/credits	(5,340)	(3,685)
Ending Balance	6,153	4,527
Other Accruals [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	34,611	35,261
Provision	27,901	18,965
Adjustments relating to prior periods	(625)	0
Payments/credits	(16,401)	(16,220)
Ending Balance	$ 45,486	$ 38,006