NET (LOSS) INCOME ATTRIBUTABLE TO COTY INC. PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Net (loss) income attributable to Coty Inc.	$ (168.8)	$ (422.2)	$ 156.9
Weighted-average common shares outstanding:
Weighted-average common shares outstanding—Basic (in shares)	749.7	642.8	345.5
Effect of dilutive stock options and Series A Preferred Stock (in shares)	0.0	0.0	5.7
Effect of restricted stock and RSUs (in shares)	0.0	0.0	3.0
Weighted-average common shares outstanding—Diluted (in shares)	749.7	642.8	354.2
Net (loss) income attributable to Coty Inc. per common share:
Basic (dollars per shares)	$ (0.23)	$ (0.66)	$ 0.45
Diluted (dollars per shares)	$ (0.23)	$ (0.66)	$ 0.44
Outstanding Stock Options and Series A Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding options excluded from diluted earnings per share calculation due to anti-dilutive effect			3.0
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding options excluded from diluted earnings per share calculation due to anti-dilutive effect			0.1