NET 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, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net (loss) income attributable to Coty Inc.	$ (77.0)	$ (164.2)	$ 12.5	$ (117.4)
Weighted-average common shares outstanding:
Weighted-average common shares outstanding—Basic (in shares)	750.1	747.3	749.4	607.9
Effect of dilutive stock options and Series A Preferred Stock (in shares)	0.0	0.0	1.3	0.0
Effect of restricted stock and RSUs (in shares)	0.0	0.0	2.4	0.0
Weighted-average common shares outstanding—Diluted (in shares)	750.1	747.3	753.1	607.9
Net (loss) income attributable to Coty Inc. per common share:
Basic (in dollars per share)	$ (0.10)	$ (0.22)	$ 0.02	$ (0.19)
Diluted (in dollars per share)	$ (0.10)	$ (0.22)	$ 0.02	$ (0.19)
Outstanding Stock Options and Series A Preferred Stock
Net (loss) income attributable to Coty Inc. per common share:
Antidilutive securities excluded from computation of earnings per share (in shares)	0.0	0.0	14.6	0.0
Restricted Stock Units (RSUs)
Net (loss) income attributable to Coty Inc. per common share:
Antidilutive securities excluded from computation of earnings per share (in shares)	0.0	0.0	2.7	0.0