REVENUE - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effect of accounting change on prior years		$ (0.1)		$ 2.3
Revenue, typical trade terms, days	We expect that at contract inception, the time period between when we transfer a promised good to our customer and our receipt of payment from that customer for that good will be one year or less (our typical trade terms are 30 to 60 days for U.S. customers and up to 90 days for our international customers).
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effect of accounting change on prior years		$ (0.1)		$ 2.3
Retained Earnings | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effect of accounting change on prior years			$ 2.3