NET INCOME (LOSS) ATTRIBUTABLE TO COTY INC. PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income (loss) attributable to Coty Inc.	$ 52.3	$ (12.1)
Weighted-average common shares outstanding:
Weighted-average common shares outstanding—Basic (in shares)	754.2	750.8
Effect of dilutive stock options and Series A Preferred Stock (in shares)	1.1	0.0
Effect of restricted stock and RSUs (in shares)	3.6	0.0
Weighted-average common shares outstanding—Diluted (in shares)	758.9	750.8
Net income (loss) attributable to Coty Inc. per common share:
Basic (in dollars per share)	$ 0.07	$ (0.02)
Diluted (in dollars per share)	$ 0.07	$ (0.02)
Outstanding Stock Options, Series A and A-1 Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	24.3
Restricted Share Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	0.6