NET (LOSS) INCOME ATTRIBUTABLE TO COTY INC. PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net (loss) income attributable to Coty Inc.	$ (12.1)	$ (77.0)	$ (984.8)	$ 12.5
Weighted-average common shares outstanding:
Weighted-average common shares outstanding—Basic (in shares)	751.4	750.1	751.1	749.4
Effect of dilutive stock options and Series A Preferred Stock (in shares)	0.0	0.0	0.0	1.3
Effect of restricted stock and RSUs (in shares)	0.0	0.0	0.0	2.4
Weighted-average common shares outstanding—Diluted (in shares)	751.4	750.1	751.1	753.1
Net (loss) income attributable to Coty Inc. per common share:
Basic (in dollars per share)	$ (0.02)	$ (0.10)	$ (1.31)	$ 0.02
Diluted (in dollars per share)	$ (0.02)	$ (0.10)	$ (1.31)	$ 0.02
Outstanding Stock Options and Series A 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)				14.6
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)				2.7