CONDENSED CONSOLIDATED STATEMENTS OF EQUITY AND REDEEMABLE NONCONTROLLING INTERESTS - USD ($) $ in Millions	Total	Class A Common Stock	Preferred Stock	Common Stock Class A Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Class A Common Stock	(Accumulated Deficit)	Accumulated Other Comprehensive (Loss) Income	Treasury Stock	Total Coty Inc. Stockholders’ Equity	Total Coty Inc. Stockholders’ Equity Class A Common Stock	Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustment due to the adoption of new accounting principle | Accounting Standards Update 2016-09	$ (112.6)						$ (112.6)			$ (112.6)
Adjustment due to the adoption of new accounting principle | Adoption of ASC 606	(18.2)						(18.2)			(18.2)
Adjusted beginning balance	8,724.4		$ 0.0	$ 8.1	$ 10,750.8		(757.0)	$ 158.8	$ (1,441.8)	8,718.9		$ 5.5
Balance, beginning of period (in shares) at Jun. 30, 2018			5,000,000.0	815,800,000					65,000,000.0
Balance, beginning of period at Jun. 30, 2018	8,855.2		$ 0.0	$ 8.1	10,750.8		(626.2)	158.8	$ (1,441.8)	8,849.7		5.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee stock options and restricted stock units	0.7				0.7					0.7
Share-based compensation expense	6.4				6.4					6.4
Dividends	(94.0)				(94.0)					(94.0)
Net (loss) income	(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 and other adjustments	(1.6)				(1.6)					(1.6)
Adjustment of redeemable noncontrolling interests to redemption value	37.2				37.2					37.2
Balance, end of period (in shares) at Sep. 30, 2018			5,000,000.0	815,800,000					65,000,000.0
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
Redeemable Noncontrolling Interests
Net income (loss)	0.8
Distribution to noncontrolling interests, net	(4.3)
Additional redeemable noncontrolling interests due to employee grants (See Note 17)	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			5,000,000.0	815,800,000					65,000,000.0
Balance, beginning of period at Jun. 30, 2018	8,855.2		$ 0.0	$ 8.1	10,750.8		(626.2)	158.8	$ (1,441.8)	8,849.7		5.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	(160.2)
Balance, end of period (in shares) at Mar. 31, 2019			8,400,000	816,400,000					65,000,000.0
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
Balance, end of period at Mar. 31, 2019	452.2
Balance, beginning of period (in shares) at Sep. 30, 2018			5,000,000.0	815,800,000					65,000,000.0
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)			3,100,000
Exercise of employee stock options and restricted stock units (in shares)				400,000
Exercise of employee stock options and restricted stock units	0.2				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	(94.6)				(94.6)					(94.6)
Net (loss) income	(960.0)						(960.6)			(960.6)		0.6
Other comprehensive income (loss)	(77.2)							(77.2)		(77.2)
Adjustment of redeemable noncontrolling interests to redemption value	126.7				126.7					126.7
Balance, end of period (in shares) at Dec. 31, 2018			1,900,000	816,200,000					65,000,000.0
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]
Cancellation of Preferred Stock (in shares)			(400,000)
Exercise of employee stock options and restricted stock units (in shares)				200,000
Exercise of employee stock options and restricted stock units	0.5				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	(94.7)				(94.7)					(94.7)
Net (loss) income	(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
Adjustment of redeemable noncontrolling interests to redemption value	33.0				33.0					33.0
Balance, end of period (in shares) at Mar. 31, 2019			8,400,000	816,400,000					65,000,000.0
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)
Additional redeemable noncontrolling interests due to employee grants (See Note 17)	0.1
Adjustment of redeemable noncontrolling interests to redemption value	(33.0)
Balance, end of period at Mar. 31, 2019	452.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustment due to the adoption of new accounting principle | Adoption of ASC 842	(0.7)						(0.7)			(0.7)
Adjusted beginning balance	4,592.7						(4,541.9)			4,586.2
Balance, beginning of period (in shares) at Jun. 30, 2019			9,400,000	819,200,000					65,000,000.0
Balance, beginning of period at Jun. 30, 2019	4,593.4		$ 0.1	$ 8.1	10,620.5		(4,541.2)	(58.8)	$ (1,441.8)	4,586.9		6.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Purchase of Class A Common Stock (in shares)									500,000
Purchase of Class A Common Stock	(4.5)								$ (4.5)	(4.5)
Exercise of employee stock options and restricted stock units (in shares)				100,000
Exercise of employee stock options and restricted stock units	0.6				0.6					0.6
Share-based compensation expense	6.2				6.2					6.2
Dividends declared - Cash and Other	(63.5)				(63.5)					(63.5)
Dividends declared - stock	(30.9)				(30.9)					(30.9)
Dividends settled in Shares of Class A Common Stock (in shares)				3,200,000
Dividends settled in Shares of Class A Common Stock		$ 30.9				$ 30.9					$ 30.9
Net (loss) income	55.1						52.3			52.3		2.8
Other comprehensive income (loss)	(124.6)							(124.6)		(124.6)
Adjustments related to the sale of business	6.2				6.2					6.2
Adjustment of redeemable noncontrolling interests to redemption value	(3.9)				(3.9)					(3.9)
Balance, end of period (in shares) at Sep. 30, 2019			9,400,000	822,500,000					65,500,000
Balance, end of period at Sep. 30, 2019	4,464.3		$ 0.1	$ 8.1	10,566.1		(4,489.6)	(183.4)	$ (1,446.3)	4,455.0		9.3
Balance, beginning of period at Jun. 30, 2019	451.8
Redeemable Noncontrolling Interests
Net income (loss)	1.2
Distribution to noncontrolling interests, net	(1.9)
Adjustments related to the sale of business	(360.4)
Adjustment of redeemable noncontrolling interests to redemption value	3.9
Balance, end of period at Sep. 30, 2019	94.6
Balance, beginning of period (in shares) at Jun. 30, 2019			9,400,000	819,200,000					65,000,000.0
Balance, beginning of period at Jun. 30, 2019	$ 4,593.4		$ 0.1	$ 8.1	10,620.5		(4,541.2)	(58.8)	$ (1,441.8)	4,586.9		6.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Purchase of Class A Common Stock (in shares)	500,000
Purchase of Class A Common Stock	$ (4.5)
Dividends settled in Shares of Class A Common Stock	88.9
Dividends	(196.5)				(196.9)
Other comprehensive income (loss)	(419.7)
Balance, end of period (in shares) at Mar. 31, 2020			1,500,000	828,600,000					65,500,000
Balance, end of period at Mar. 31, 2020	3,961.1		$ 0.0	$ 8.3	10,431.0		(4,782.3)	(478.5)	$ (1,446.3)	3,732.2		228.9
Balance, beginning of period at Jun. 30, 2019	451.8
Balance, end of period at Mar. 31, 2020	98.7
Balance, beginning of period (in shares) at Sep. 30, 2019			9,400,000	822,500,000					65,500,000
Balance, beginning of period at Sep. 30, 2019	4,464.3		$ 0.1	$ 8.1	10,566.1		(4,489.6)	(183.4)	$ (1,446.3)	4,455.0		9.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee stock options and restricted stock units (in shares)				1,100,000
Exercise of employee stock options and restricted stock units	1.5				1.5					1.5
Shares withheld for employee taxes	(3.5)				(3.5)					(3.5)
Share-based compensation expense	10.3				10.3					10.3
Dividends declared - Cash and Other	(66.1)				(66.1)					(66.1)
Dividends declared - stock	(29.3)				(29.3)					(29.3)
Dividends settled in Shares of Class A Common Stock (in shares)				2,400,000
Dividends settled in Shares of Class A Common Stock		29.5		$ 0.2		29.3					29.5
Net (loss) income	(20.6)						(21.1)			(21.1)		0.5
Other comprehensive income (loss)	106.0							105.9		105.9		0.1
Adjustment of redeemable noncontrolling interests to redemption value	(10.5)				(10.5)					(10.5)
Balance, end of period (in shares) at Dec. 31, 2019			9,400,000	826,000,000.0					65,500,000
Balance, end of period at Dec. 31, 2019	4,481.6		$ 0.1	$ 8.3	10,497.8		(4,510.7)	(77.5)	$ (1,446.3)	4,471.7		9.9
Balance, beginning of period at Sep. 30, 2019	94.6
Redeemable Noncontrolling Interests
Net income (loss)	4.2
Distribution to noncontrolling interests, net	(10.7)
Adjustment of redeemable noncontrolling interests to redemption value	10.5
Balance, end of period at Dec. 31, 2019	98.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Preferred Stock (in shares)			6,900,000
Issuance of Preferred Stock	0.7		$ 0.1		0.6					0.7
Cancellation of Preferred Stock (in shares)			(7,900,000)
Cancellation of Preferred Stock	(0.7)		$ (0.1)		(0.6)					(0.7)
Exercise of employee stock options and restricted stock units (in shares)				200,000
Exercise of employee stock options and restricted stock units	0.6				0.6					0.6
Shares withheld for employee taxes	(0.3)				(0.3)					(0.3)
Share-based compensation expense	3.5				3.5					3.5
Dividends declared - Cash and Other	(66.9)				(66.9)					(66.9)
Dividends declared - stock	(28.7)				(28.7)					(28.7)
Dividends settled in Shares of Class A Common Stock (in shares)				2,400,000
Dividends settled in Shares of Class A Common Stock		$ 28.7				$ 28.7					$ 28.7
Net (loss) income	(265.4)						(271.6)			(271.6)		6.2
Other comprehensive income (loss)	(401.1)							(401.0)		(401.0)		(0.1)
Noncontrolling interest due to transaction (See Note 5)	212.9											212.9
Adjustment of redeemable noncontrolling interests to redemption value	(3.1)				(3.1)					(3.1)
Balance, end of period (in shares) at Mar. 31, 2020			1,500,000	828,600,000					65,500,000
Balance, end of period at Mar. 31, 2020	3,961.1		$ 0.0	$ 8.3	$ 10,431.0		$ (4,782.3)	$ (478.5)	$ (1,446.3)	$ 3,732.2		$ 228.9
Redeemable Noncontrolling Interests
Net income (loss)	1.0
Distribution to noncontrolling interests, net	(4.0)
Adjustment of redeemable noncontrolling interests to redemption value	3.1
Balance, end of period at Mar. 31, 2020	$ 98.7