CONDENSED CONSOLIDATED STATEMENTS OF EQUITY AND REDEEMABLE NONCONTROLLING INTERESTS - USD ($) shares in Millions, $ in Millions	Total	Preferred Stock	Common Stock Class A Common Stock	Additional Paid-in Capital	(Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total Coty Inc. Stockholders’ Equity	Noncontrolling Interests	As Previously Reported	As Previously Reported Preferred Stock	As Previously Reported Common Stock Class A Common Stock	As Previously Reported Additional Paid-in Capital	As Previously Reported (Accumulated Deficit)	As Previously Reported Accumulated Other Comprehensive Income (Loss)	As Previously Reported Treasury Stock	As Previously Reported Total Coty Inc. Stockholders’ Equity	As Previously Reported Noncontrolling Interests	As Adjusted	As Adjusted Preferred Stock	As Adjusted Common Stock Class A Common Stock	As Adjusted Additional Paid-in Capital	As Adjusted (Accumulated Deficit)	As Adjusted Accumulated Other Comprehensive Income (Loss)	As Adjusted Treasury Stock	As Adjusted Total Coty Inc. Stockholders’ Equity	As Adjusted Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustment due to the adoption of ASU | Accounting Standards Update 2016-09																			$ 8.3				$ 8.3			$ 8.3
Balance, beginning of period (in shares) at Jun. 30, 2017											4.2	812.9				65.0				4.2	812.9				65.0
Balance, beginning of period at Jun. 30, 2017						$ 4.4				$ 9,317.7	$ 0.0	$ 8.1	$ 11,203.2	$ (459.2)	$ 4.4	$ (1,441.8)	$ 9,314.7	$ 3.0	9,326.0	$ 0.0	$ 8.1	$ 11,203.2	(450.9)	$ 4.4	$ (1,441.8)	9,323.0	$ 3.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee stock options and restricted stock units and related tax benefits (in shares)			1.5
Exercise of employee stock options and restricted stock units and related tax benefits	$ 11.2		$ 0.0	$ 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 ($0.125 per common share)	(94.3)			(94.3)				(94.3)
Net income (loss)	(21.9)				$ (19.7)			(19.7)	$ (2.2)
Other comprehensive income (loss)	239.7					239.1		239.1	0.6
Additional redeemable noncontrolling interests due to employee grants and other adjustments	17.0			17.0				17.0
Adjustment of redeemable noncontrolling interests to the higher of its redemption value or carrying 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, beginning of period at Jun. 30, 2017										551.1									551.1
Redeemable Noncontrolling Interests
Net income (loss)	5.8
Distribution to noncontrolling interests, net	(6.4)
Dilution of redeemable noncontrolling interest due to additional contribution	(17.0)
Adjustment of redeemable noncontrolling interests to redemption value	29.0
Balance, end of period at Sep. 30, 2017	562.5
Balance, beginning of period (in shares) at Jun. 30, 2017											4.2	812.9				65.0				4.2	812.9				65.0
Balance, beginning of period at Jun. 30, 2017						4.4				9,317.7	$ 0.0	$ 8.1	11,203.2	(459.2)	4.4	$ (1,441.8)	9,314.7	3.0	9,326.0	$ 0.0	$ 8.1	11,203.2	(450.9)	4.4	$ (1,441.8)	9,323.0	3.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	532.0
Balance, end of period (in shares) at Mar. 31, 2018		5.0	815.5				65.0
Balance, end of period at Mar. 31, 2018	9,499.6	$ 0.0	$ 8.1	10,835.3	(438.4)	536.1	$ (1,441.8)	9,499.3	0.3
Balance, beginning of period at Jun. 30, 2017										551.1									551.1
Redeemable Noncontrolling Interests
Proceeds from noncontrolling interests	0.2
Balance, end of period at Mar. 31, 2018	665.4
Balance, beginning of period (in shares) at Sep. 30, 2017		4.2	814.4				65.0
Balance, beginning 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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Preferred Stock (in shares)		1.0
Issuance of Preferred Stock	0.0							0.0
Exercise of employee stock options and restricted stock units and related tax benefits (in shares)			0.4
Exercise of employee stock options and restricted stock units and related tax benefits	2.5			2.5				2.5
Shares withheld for employee taxes	(0.3)			(0.3)				(0.3)
Share-based compensation expense	9.0			9.0				9.0
Dividends ($0.125 per common share)	(94.4)			(94.4)				(94.4)
Net income (loss)	107.3				109.2			109.2	(1.9)
Other comprehensive income (loss)	40.3					40.4		40.4	(0.1)
Additional redeemable noncontrolling interests due to employee grants (See Note 17)	(8.3)			(8.3)				(8.3)
Adjustment of redeemable noncontrolling interests to the higher of its redemption value or carrying value	(81.3)			(81.3)				(81.3)
Balance, end of period (in shares) at Dec. 31, 2017		5.2	814.8				65.0
Balance, end of period at Dec. 31, 2017	9,428.5	$ 0.0	$ 8.1	10,940.3	(361.4)	283.9	$ (1,441.8)	9,429.1	(0.6)
Balance, beginning of period at Sep. 30, 2017	562.5
Redeemable Noncontrolling Interests
Net income (loss)	11.3
Distribution to noncontrolling interests, net	(25.3)
Additional redeemable noncontrolling interests due to employee grants	8.3
Proceeds from noncontrolling interests	0.2
Adjustment of redeemable noncontrolling interests to redemption value	81.3
Balance, end of period at Dec. 31, 2017	638.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cancellation of Preferred Stock (in shares)		(0.2)
Cancellation of Preferred Stock		$ 0.0
Exercise of employee stock options and restricted stock units and related tax benefits (in shares)			0.7
Exercise of employee stock options and restricted stock units and related tax benefits	6.3			6.3				6.3
Shares withheld for employee taxes	(0.1)			(0.1)				(0.1)
Share-based compensation expense	8.7			8.7				8.7
Dividends ($0.125 per common share)	(94.6)			(94.6)				(94.6)
Net income (loss)	(75.9)				(77.0)			(77.0)	1.1
Other comprehensive income (loss)	252.0					252.2		252.2	(0.2)
Additional redeemable noncontrolling interests due to employee grants (See Note 17)	0.9			0.9				0.9
Adjustment of redeemable noncontrolling interests to the higher of its redemption value or carrying value	(26.2)			(26.2)				(26.2)
Balance, end of period (in shares) at Mar. 31, 2018		5.0	815.5				65.0
Balance, end of period at Mar. 31, 2018	9,499.6	$ 0.0	$ 8.1	10,835.3	(438.4)	536.1	$ (1,441.8)	9,499.3	0.3
Redeemable Noncontrolling Interests
Net income (loss)	15.8
Distribution to noncontrolling interests, net	(14.0)
Additional redeemable noncontrolling interests due to employee grants	(0.9)
Adjustment of redeemable noncontrolling interests to redemption value	26.2
Balance, end of period at Mar. 31, 2018	665.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustment due to the adoption of ASU | Accounting Standards Update 2016-16																			(112.6)				(112.6)			(112.6)
Adjustment due to the adoption of ASU | Accounting Standards Update 2014-09																			(18.2)				(18.2)			(18.2)
Balance, beginning of period (in shares) at Jun. 30, 2018											5.0	815.8				65.0				5.0	815.8				65.0
Balance, beginning of period at Jun. 30, 2018	8,855.2					158.8				8,855.2	$ 0.0	$ 8.1	10,750.8	(626.2)	158.8	$ (1,441.8)	8,849.7	5.5	8,724.4	$ 0.0	$ 8.1	10,750.8	(757.0)	158.8	$ (1,441.8)	8,718.9	5.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee stock options and restricted stock units and related tax benefits (in shares)			0.0
Exercise of employee stock options and restricted stock units and related tax benefits	0.7		$ 0.0	0.7				0.7
Share-based compensation expense	6.4			6.4				6.4
Dividends ($0.125 per common share)	(94.0)			(94.0)				(94.0)
Net income (loss)	(10.9)				(12.1)			(12.1)	1.2
Other comprehensive income (loss)	(47.8)					(48.0)		(48.0)	0.2
Distribution to noncontrolling interests, net	(1.3)								(1.3)
Additional redeemable noncontrolling interests due to employee grants (See Note 17)	(1.6)			(1.6)				(1.6)
Adjustment of redeemable noncontrolling interests to the higher of its redemption value or carrying value	37.2			37.2				37.2
Balance, end of period (in shares) at Sep. 30, 2018		5.0	815.8				65.0
Balance, end of period at Sep. 30, 2018	8,613.1	$ 0.0	$ 8.1	10,699.5	(769.1)	110.8	$ (1,441.8)	8,607.5	5.6
Balance, beginning of period at Jun. 30, 2018										661.3									661.3
Redeemable Noncontrolling Interests
Net income (loss)	0.8
Distribution to noncontrolling interests, net	(4.3)
Additional redeemable noncontrolling interests due to employee grants	1.6
Adjustment of redeemable noncontrolling interests to redemption value	(37.2)
Balance, end of period at Sep. 30, 2018	622.2
Balance, beginning of period (in shares) at Jun. 30, 2018											5.0	815.8				65.0				5.0	815.8				65.0
Balance, beginning of period at Jun. 30, 2018	8,855.2					158.8				8,855.2	$ 0.0	$ 8.1	$ 10,750.8	$ (626.2)	$ 158.8	$ (1,441.8)	$ 8,849.7	$ 5.5	8,724.4	$ 0.0	$ 8.1	$ 10,750.8	$ (757.0)	$ 158.8	$ (1,441.8)	$ 8,718.9	$ 5.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends ($0.125 per common share)				(282.8)
Other comprehensive income (loss)	(160.2)
Additional redeemable noncontrolling interests due to employee grants (See Note 17)				(1.7)
Balance, end of period (in shares) at Mar. 31, 2019		8.4	816.4				65.0
Balance, end of period at Mar. 31, 2019	7,502.5	$ 0.1	$ 8.1	10,674.6	(1,741.8)	(1.5)	$ (1,441.8)	7,497.7	4.8
Balance, beginning of period at Jun. 30, 2018										$ 661.3									$ 661.3
Redeemable Noncontrolling Interests
Additional redeemable noncontrolling interests due to employee grants	1.7
Proceeds from noncontrolling interests	0.0
Balance, end of period at Mar. 31, 2019	452.2
Balance, beginning of period (in shares) at Sep. 30, 2018		5.0	815.8				65.0
Balance, beginning of period at Sep. 30, 2018	8,613.1	$ 0.0	$ 8.1	10,699.5	(769.1)	110.8	$ (1,441.8)	8,607.5	5.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cancellation of Preferred Stock (in shares)		(3.1)
Cancellation of Preferred Stock		$ 0.0
Exercise of employee stock options and restricted stock units and related tax benefits (in shares)			0.4
Exercise of employee stock options and restricted stock units and related tax benefits	0.2		$ 0.0	0.2				0.2
Shares withheld for employee taxes	(1.3)			(1.3)				(1.3)
Share-based compensation expense	4.4			4.4				4.4
Dividends ($0.125 per common share)	(94.6)			(94.6)				(94.6)
Net income (loss)	(960.0)				(960.6)			(960.6)	0.6
Other comprehensive income (loss)	(77.2)					(77.2)		(77.2)
Adjustment of redeemable noncontrolling interests to the higher of its redemption value or carrying value	126.7			126.7				126.7
Balance, end of period (in shares) at Dec. 31, 2018		1.9	816.2				65.0
Balance, end of period at Dec. 31, 2018	7,611.3	$ 0.0	$ 8.1	10,734.9	(1,729.7)	33.6	$ (1,441.8)	7,605.1	6.2
Balance, beginning of period at Sep. 30, 2018	622.2
Redeemable Noncontrolling Interests
Net income (loss)	4.0
Distribution to noncontrolling interests, net	(11.9)
Adjustment of redeemable noncontrolling interests to redemption value	(126.7)
Balance, end of period at Dec. 31, 2018	487.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Preferred Stock (in shares)		6.9
Issuance of Preferred Stock	0.7	$ 0.1		0.6				0.7
Cancellation of Preferred Stock (in shares)		(0.4)
Cancellation of Preferred Stock		$ 0.0
Exercise of employee stock options and restricted stock units and related tax benefits (in shares)			0.2
Exercise of employee stock options and restricted stock units and related tax benefits	0.5		$ 0.0	0.5				0.5
Shares withheld for employee taxes	(0.1)			(0.1)				(0.1)
Share-based compensation expense	(0.5)			(0.5)				(0.5)
Dividends ($0.125 per common share)	(94.7)			(94.7)				(94.7)
Net income (loss)	(9.8)				(12.1)			(12.1)	2.3
Other comprehensive income (loss)	(35.2)					(35.1)		(35.1)	(0.1)
Distribution to noncontrolling interests, net	(3.6)								(3.6)
Additional redeemable noncontrolling interests due to employee grants and other adjustments	0.9			0.9				0.9
Additional redeemable noncontrolling interests due to employee grants (See Note 17)				(1.7)
Adjustment of redeemable noncontrolling interests to the higher of its redemption value or carrying value	33.0			33.0				33.0
Balance, end of period (in shares) at Mar. 31, 2019		8.4	816.4				65.0
Balance, end of period at Mar. 31, 2019	7,502.5	$ 0.1	$ 8.1	$ 10,674.6	$ (1,741.8)	$ (1.5)	$ (1,441.8)	$ 7,497.7	$ 4.8
Redeemable Noncontrolling Interests
Net income (loss)	5.8
Distribution to noncontrolling interests, net	(8.3)
Dilution of redeemable noncontrolling interest due to additional contribution	0.1
Additional redeemable noncontrolling interests due to employee grants	1.7
Adjustment of redeemable noncontrolling interests to redemption value	(33.0)
Balance, end of period at Mar. 31, 2019	$ 452.2