CONDENSED CONSOLIDATED STATEMENTS OF EQUITY AND REDEEMABLE NONCONTROLLING INTERESTS (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Preferred Stock	Common Stock	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Additional Paid-in Capital	(Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total Coty Inc. Stockholders’ Equity	Noncontrolling Interests
Balance as previously reported (in shares) at Jun. 30, 2016		1.7		138.7	262.0				63.6
Balance, beginning of period at Jun. 30, 2016	$ 367.1	$ 0.0		$ 1.4	$ 2.6	$ 2,038.4	$ (37.0)	$ (239.7)	$ (1,405.5)	$ 360.2	$ 6.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee stock options and restricted stock units (in shares)				0.7
Exercise of employee stock options and restricted stock units	6.2			$ 0.1		6.1				6.2
Share-based compensation expense	2.9					2.9				2.9
Dividends	(93.3)					(93.3)				(93.3)
Net (loss) income	8.2									0.0	8.2
Other comprehensive income	7.8							7.8		7.8
Adjustment of redeemable noncontrolling interests to redemption value	3.5					3.5				3.5
Conversion of Class B to Class A Common Stock (in shares)				262.0	(262.0)
Conversion of Class B to Class A Common Stock				$ 2.6	$ (2.6)					0.0
Purchase of Class A Common Stock (in shares)									1.4
Purchase of Class A Common Stock	(36.3)								$ (36.3)	(36.3)
Distribution to noncontrolling interests, net	0.0									0.0
Balance, end of period (in shares) at Sep. 30, 2016		1.7		401.4	0.0				65.0
Balance, end of period at Sep. 30, 2016	266.1	$ 0.0		$ 4.1	$ 0.0	1,957.6	(37.0)	(231.9)	$ (1,441.8)	251.0	15.1
BALANCE as previously reported—July 1, 2017 at Jun. 30, 2016	73.3
Increase (Decrease) in Redeemable Noncontrolling Interests [Roll Forward]
Net (loss) income	1.6
Distribution to noncontrolling interests, net	(1.1)
Adjustment of redeemable noncontrolling interests to redemption value	(3.5)
Balance, end of period at Sep. 30, 2016	70.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustment due to the adoption of ASU 2016-09 (see Note 2)	8.3						8.3			8.3
BALANCE as adjusted—July 1, 2017	9,326.0	$ 0.0	$ 8.1			11,203.2	(450.9)	4.4	$ (1,441.8)	9,323.0	3.0
Balance as previously reported (in shares) at Jun. 30, 2017		4.2	812.9						65.0
Balance, beginning of period at Jun. 30, 2017	9,317.7	$ 0.0	$ 8.1			11,203.2	(459.2)	4.4	$ (1,441.8)	9,314.7	3.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee stock options and restricted stock units (in shares)			1.5
Exercise of employee stock options and restricted stock units	11.2					11.2				11.2
Shares withheld for employee taxes	(3.1)					(3.1)				(3.1)
Share-based compensation expense	8.1					8.1				8.1
Dividends	(94.3)					(94.3)				(94.3)
Net (loss) income	(21.9)						(19.7)			(19.7)	(2.2)
Other comprehensive income	239.7							239.1		239.1	0.6
Dilution of redeemable noncontrolling interest due to additional contribution (see Note 16)	17.0					17.0				17.0
Adjustment of redeemable noncontrolling interests to redemption value	(29.0)					(29.0)				(29.0)
Balance, end of period (in shares) at Sep. 30, 2017		4.2	814.4						65.0
Balance, end of period at Sep. 30, 2017	9,453.7	$ 0.0	$ 8.1			$ 11,113.1	$ (470.6)	$ 243.5	$ (1,441.8)	$ 9,452.3	$ 1.4
BALANCE as previously reported—July 1, 2017 at Jun. 30, 2017	551.1
Increase (Decrease) in Redeemable Noncontrolling Interests [Roll Forward]
Net (loss) income	5.8
Distribution to noncontrolling interests, net	(6.4)
Adjustment of redeemable noncontrolling interests to redemption value	29.0
Balance, end of period at Sep. 30, 2017	$ 562.5