SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)	12 Months Ended
	Jun. 30, 2018 USD ($) unit	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($) segment	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)
Significant Accounting Policies [Line Items]
Foreign earnings repatriated			$ 4,500,000,000
Restricted cash	$ 30,600,000	$ 30,600,000	30,600,000	$ 30,600,000	$ 35,300,000
Number of reporting units	3			3
Sales returns, percentage		2.00%			2.00%	3.00%
Trade spending activities, percentage		8.00%			7.00%	8.00%
Advertising expense			2,206,300,000		$ 1,883,300,000	$ 967,600,000
Depreciation and amortization			384,200,000		280,000,000	152,400,000
Research and development expense			174,600,000		139,200,000	47,700,000
Deferred financing fees	$ 86,200,000	$ 86,200,000	86,200,000	$ 86,200,000	67,600,000
Cumulative effect of new accounting principle in period of adoption					8,300,000
Payments related to tax withholding for share-based compensation			3,600,000
Operating Income (Loss)
Significant Accounting Policies [Line Items]
Net losses (gains) from foreign currency exchange transactions			3,900,000		1,500,000	7,200,000
Interest Expense, Net and Other Expense (Income), Net
Significant Accounting Policies [Line Items]
Net losses (gains) from foreign currency exchange transactions			8,500,000		(12,800,000)	19,200,000
Other Expense, Net
Significant Accounting Policies [Line Items]
Net losses (gains) from foreign currency exchange transactions			0		1,700,000	29,400,000
Marketing furniture and fixtures
Significant Accounting Policies [Line Items]
Depreciation and amortization			120,900,000		107,400,000	$ 65,000,000
Accumulated Deficit
Significant Accounting Policies [Line Items]
Cumulative effect of new accounting principle in period of adoption	$ (6,500,000)	$ (6,500,000)	(6,500,000)	$ (6,500,000)	$ 8,300,000
Pro Forma | Accounting Standards Update 2014-09
Significant Accounting Policies [Line Items]
Revenues			$ 25,200,000