Product Revenues, Net, Accounts Receivable, Net, and Reserves for Product Revenues - Summary of Change in Reserves for Discounts and Allowances (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	$ 200,036	$ 194,299
Provision	258,027	389,898
Adjustments relating to prior periods	(11,724)	(10,952)
Payments/credits	(276,670)	(384,054)
Ending Balance	169,669	189,191
Chargebacks [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	25,563	45,904
Provision	66,296	159,510
Adjustments relating to prior periods	0	0
Payments/credits	(76,682)	(185,724)
Ending Balance	15,177	19,690
Rebates [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	116,585	107,843
Provision	115,320	148,822
Adjustments relating to prior periods	(10,274)	(10,327)
Payments/credits	(113,427)	(118,600)
Ending Balance	108,204	127,738
Prompt Pay [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	3,831	5,941
Provision	11,900	15,702
Adjustments relating to prior periods	1,429	0
Payments/credits	(10,158)	(17,498)
Ending Balance	4,144	4,145
Other Accruals [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning Balance	54,057	34,611
Provision	64,511	65,864
Adjustments relating to prior periods	(21)	(625)
Payments/credits	(76,403)	(62,232)
Ending Balance	$ 42,144	$ 37,618