ACCOUNTS PAYABLE AND ACCRUED EXPENSES - Schedule of Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounts Payable and Accrued Liabilities, Current [Abstract]
Trade accounts payable	$ 111,045	$ 94,408
Returns and allowances	180,269	207,916
Rebates	158,368	126,644
Chargebacks	3,124	2,177
Other sales deductions	2,843	0
Accrued interest	162,502	98,105
Accrued payroll and related benefits	111,426	130,092
Accrued royalties and other distribution partner payables	47,665	59,745
Acquisition-related contingent consideration—current	5,605	8,566
Other	138,169	108,287
Total	$ 921,016	$ 835,940