DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accruals and allowances (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Accruals and allowances
Beginning balance	$ 59,946
Ending balance	100,328	$ 59,946
Sales of contract manufactured products [Member]
Accruals and allowances
Revenue, Remaining Performance Obligation, Amount	$ 6,800
Revenue, Remaining Performance Obligation, Remaining Period	12 months
Product Development Services [Member]
Accruals and allowances
Revenue, Remaining Performance Obligation, Amount	$ 600
Product Development Services [Member] \| Maximum
Accruals and allowances
Revenue, Remaining Performance Obligation, Remaining Period	18 months
Chargebacks
Accruals and allowances
Beginning balance	$ 49,882	39,007
Accruals/Adjustments	408,265	260,771
Credits Taken Against Reserve	(369,401)	(249,896)
Ending balance	88,746	49,882
Government Rebates
Accruals and allowances
Beginning balance	8,901	8,974
Accruals/Adjustments	14,240	17,549
Credits Taken Against Reserve	(15,315)	(17,622)
Ending balance	7,826	8,901
Returns
Accruals and allowances
Beginning balance	16,595	12,552
Accruals/Adjustments	30,333	19,105
Credits Taken Against Reserve	(19,773)	(15,062)
Ending balance	27,155	16,595
Administrative Fees and Other Rebates
Accruals and allowances
Beginning balance	8,281	7,353
Accruals/Adjustments	37,588	36,874
Credits Taken Against Reserve	(36,963)	(35,946)
Ending balance	8,906	8,281
Prompt Payment Discounts
Accruals and allowances
Beginning balance	2,549	2,009
Accruals/Adjustments	14,347	10,789
Credits Taken Against Reserve	(13,057)	(10,249)
Ending balance	$ 3,839	$ 2,549

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (a)
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Remaining duration of performance obligation for which optional exemption was applied not to disclose amount of transaction price allocated to and timing of revenue recognition for remaining performance obligation, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130558-203045

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- Definition

Amount of increase (decrease) in valuation and qualifying accounts and reserves from adjustment.

+ 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.

+ References

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))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690

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-Name Accounting Standards Codification
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Amount of decrease in valuation and qualifying accounts and reserves.

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