REVENUE RECOGNITION (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jul. 01, 2018	Jun. 30, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Property and equipment, net	$ 1,625.7		$ 1,625.7		$ 1,674.6	$ 1,680.8
Deferred income taxes	182.7		182.7		108.0	107.4
Other noncurrent assets	153.5		153.5		306.4	299.5
Accrued expenses and other current liabilities	1,738.8		1,738.8		1,865.1	1,844.4
Deferred income taxes	840.6		840.6		841.3	842.5
Accumulated deficit	(1,729.7)		(1,729.7)		$ (644.4)	(626.2)
Net revenues	2,511.2	$ 2,637.6	4,542.5	$ 4,875.9
Selling, general and administrative expenses	1,284.0	1,319.2	2,406.3	2,510.3
Net loss	(956.0)	118.6	(966.1)	102.5
Net loss attributable to Coty Inc.	$ (960.6)	$ 109.2	$ (972.7)	$ 89.5
Basic (in usd per share)	$ (1.28)	$ 0.15	$ (1.30)	$ 0.12
Diluted (in usd per share)	$ (1.28)	$ 0.15	$ (1.30)	$ 0.12
Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Property and equipment, net						1,680.8
Deferred income taxes						107.4
Other noncurrent assets						299.5
Accrued expenses and other current liabilities						1,844.4
Deferred income taxes						842.5
Accumulated deficit						(626.2)
Net revenues	$ 2,487.3		$ 4,525.8
Selling, general and administrative expenses	1,284.2		2,407.6
Net loss	(974.3)		(979.5)
Net loss attributable to Coty Inc.	$ (978.7)		$ (986.3)
Basic (in usd per share)	$ (1.30)		$ (1.32)
Diluted (in usd per share)	$ (1.30)		$ (1.32)
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Property and equipment, net						(6.2)
Deferred income taxes						0.6
Other noncurrent assets						6.9
Accrued expenses and other current liabilities						20.7
Deferred income taxes						(1.2)
Accumulated deficit						$ (18.2)
Net revenues	$ (23.9)		$ (16.7)
Selling, general and administrative expenses	0.2		1.3
Net loss	(18.3)		(13.4)
Net loss attributable to Coty Inc.	$ (18.1)		$ (13.6)
Basic (in usd per share)	$ (0.02)		$ (0.02)
Diluted (in usd per share)	$ (0.02)		$ (0.02)
Furniture and Fixtures | Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Property, plant and equipment			3 years
Furniture and Fixtures | Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Property, plant and equipment			5 years