REVENUE RECOGNITION AND RELATED ALLOWANCES - Allowances (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020
Accruals and allowances
Beginning balance	$ 100,328
Ending balance	108,456
Chargebacks
Accruals and allowances
Beginning balance	88,746	$ 49,882
Accruals/Adjustments	343,117	288,538
Credits Taken Against Reserve	(333,867)	(262,531)
Ending balance	97,996	75,889
Government Rebates
Accruals and allowances
Beginning balance	7,826	8,901
Accruals/Adjustments	31,515	14,288
Credits Taken Against Reserve	(27,628)	(11,511)
Ending balance	11,713	11,678
Returns
Accruals and allowances
Beginning balance	27,155	16,595
Accruals/Adjustments	16,043	22,744
Credits Taken Against Reserve	(10,969)	(16,089)
Ending balance	32,229	23,250
Administrative Fees and Other Rebates
Accruals and allowances
Beginning balance	8,906	8,281
Accruals/Adjustments	74,594	27,383
Credits Taken Against Reserve	(75,877)	(27,287)
Ending balance	7,623	8,377
Prompt Payment Discounts
Accruals and allowances
Beginning balance	3,839	2,549
Accruals/Adjustments	31,138	10,248
Credits Taken Against Reserve	(30,876)	(9,442)
Ending balance	$ 4,101	$ 3,355

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
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Amount of valuation and qualifying accounts and reserves.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09(Column B))
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
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-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09(Column E))
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