NET INCOME (LOSS) ATTRIBUTABLE TO COTY INC. PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2022
Amounts attributable to Coty Inc.:
Net income (loss) from continuing operations	$ 89.4	$ 508.2	$ 253.8
Convertible Series B Preferred Stock dividends	(13.2)	(13.2)	(198.3)
Net income from continuing operations attributable to common stockholders	76.2	495.0	55.5
Net income (loss) from discontinued operations, net of tax	0.0	0.0	5.7
Net income from continuing operations attributable to common stockholders	$ 76.2	$ 495.0	$ 61.2
Weighted-average common shares outstanding:
Weighted-average common shares outstanding—Basic (in shares)	874.4	849.0	820.6
Effect of dilutive stock options and Series A Preferred Stock (in shares)	0.1	0.0	0.0
Effect of restricted stock, PRSUs and RSUs (in shares)	8.9	13.8	13.5
Effect of Convertible Series B Preferred Stock (in shares)	0.0	23.7	0.0
Effect of Forward Repurchase Contracts	0.0	0.0	0.0
Weighted-average common shares and common share equivalents outstanding—Diluted (in shares)	883.4	886.5	834.1
Earnings (losses) per common share
Earnings from continuing operations per common share - basic (in dollars per share)	$ 0.09	$ 0.58	$ 0.07
Earnings (losses) from continuing operations per common share - diluted (in dollars per share)	0.09	0.57	0.07
Earnings from discontinued operations - basic (in dollars per share)	0.00	0.00	0.01
Earnings from discontinued operations - diluted (in dollars per share)	0.00	0.00	0.01
Earnings per common share - basic (in dollars per share)	0.09	0.58	0.08
Earnings per common share - diluted (in dollars per share)	$ 0.09	$ 0.57	$ 0.08
Convertible Series B Preferred Stock dividends	$ 13.2	$ 13.2	$ 198.3
Antidilutive​ fair market value adjustments	$ 73.4	$ (101.8)	$ 0.0
Share-Based Payment Arrangement, Option and Series A Preferred Stock
Earnings (losses) per common share
Anti-dilutive shares (in shares)	2.8	4.8	8.3
Restricted Stock Units
Earnings (losses) per common share
Anti-dilutive shares (in shares)	1.0	3.2	1.6
Convertible Series B Preferred Stock
Earnings (losses) per common share
Anti-dilutive shares (in shares)	23.7		65.4