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Revenue Recognition - Summarize Activity of the Net Product Revenue Allowance and Reserve Categories (Detail) - USD ($) $ in Thousands | 9 Months Ended
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Sep. 30, 2021 | Sep. 30, 2020
Valuation And Qualifying Accounts Disclosure [Line Items] |  |
Beginning balance | $ 190,827 | $ 128,557
Provision related to current period sales | 627,571 | 585,206
Provision related to prior period sales | (854) | (3,872)
Credits/payments made for current period sales | (362,460) | (384,035)
Credits/payments made for prior period sales | (172,378) | (118,742)
Ending balance | 282,706 | 207,114
Trade Allowances |  |
Valuation And Qualifying Accounts Disclosure [Line Items] |  |
Beginning balance | 36,242 | 29,261
Provision related to current period sales | 90,761 | 95,239
Credits/payments made for current period sales | (27,635) | (32,364)
Credits/payments made for prior period sales | (34,511) | (29,067)
Ending balance | 64,857 | 63,069
Rebates, Chargebacks and Discounts |  |
Valuation And Qualifying Accounts Disclosure [Line Items] |  |
Beginning balance | 141,201 | 90,997
Provision related to current period sales | 497,726 | 437,030
Provision related to prior period sales | (854) | (3,872)
Credits/payments made for current period sales | (303,029) | (304,903)
Credits/payments made for prior period sales | (131,320) | (85,731)
Ending balance | 203,724 | 133,521
Product Returns |  |
Valuation And Qualifying Accounts Disclosure [Line Items] |  |
Beginning balance | 7,797 | 4,579
Provision related to current period sales | 2,647 | 2,534
Credits/payments made for prior period sales | (958) | (223)
Ending balance | 9,486 | 6,890
Other Incentives |  |
Valuation And Qualifying Accounts Disclosure [Line Items] |  |
Beginning balance | 5,587 | 3,720
Provision related to current period sales | 36,437 | 50,403
Credits/payments made for current period sales | (31,796) | (46,768)
Credits/payments made for prior period sales | (5,589) | (3,721)
Ending balance | $ 4,639 | $ 3,634

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