REVENUE RECOGNITION - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Rebates	$ (198,547,000)	$ (172,832,000)	$ (549,670,000)	$ (485,936,000)
Revenue recognized fro performance obligation satisfied in previous period	0	0	0	0
Gross receivables from contracts	90,291,000		90,291,000		$ 73,500,000
Contract liabilities	2,812,000		2,812,000		$ 3,074,000
Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Rebates	$ 1,027,000	$ 1,648,000	$ 3,474,000	$ 4,732,000