NET INCOME ATTRIBUTABLE TO COTY INC. PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income attributable to Coty Inc.	$ 109.2	$ 46.8	$ 89.5	$ 46.8
Weighted-average common shares outstanding:
Weighted-average common shares outstanding—Basic (in shares)	749.6	746.6	749.1	539.8
Effect of dilutive stock options and Series A Preferred Stock (in shares)	1.2	2.7	1.4	3.2
Effect of restricted stock and RSUs (in shares)	1.9	3.1	2.0	2.8
Weighted-average common shares outstanding—Diluted (in shares)	752.7	752.4	752.5	545.8
Net income attributable to Coty Inc. per common share:
Basic (in dollars per share)	$ 0.15	$ 0.06	$ 0.12	$ 0.09
Diluted (in dollars per share)	$ 0.15	$ 0.06	$ 0.12	$ 0.09
Outstanding Stock Options and Series A Preferred Stock
Net income attributable to Coty Inc. per common share:
Antidilutive securities excluded from computation of earnings per share (in shares)	15.3	10.8	13.6	6.4
Restricted Stock Units (RSUs)
Net income attributable to Coty Inc. per common share:
Antidilutive securities excluded from computation of earnings per share (in shares)	2.6	1.1	4.1	0.6