FAIR VALUE MEASUREMENTS - Contingent Consideration Roll forward (Details) - USD ($) $ in Millions	3 Months Ended							12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Business Combination, Contingent Consideration [Roll Forward]
Changes in fair value	$ (8)	$ (2)	$ (7)	$ (19)	$ (9)	$ 2	$ (11)	$ (17)	$ (37)	$ (43)
Selling, general and administrative expenses
Business Combination, Contingent Consideration [Roll Forward]
Contingent consideration at June 30, 2019								36
Payments								(15)
Changes in fair value								(17)
Contingent consideration at June 30, 2020	$ 4			$ 36				$ 4	$ 36