Schedule II Valuation and Qualifying Accounts and Reserves Schedule II (Details) - USD ($) $ in Millions		12 Months Ended
		May 31, 2018	May 31, 2017	May 31, 2016
Allowance for doubtful accounts [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		$ 13.7	$ 16.1	$ 14.9
Expensed		9.5	11.0	12.3
Write-Offs and Other		10.8	13.4	11.1
Balance at End of Year		12.4	13.7	16.1
Reserve For Return [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		36.3	32.1	27.9
Expensed		54.5	80.4	56.6
Write-Offs and Other	[1]	60.8	76.2	52.4
Balance at End of Year		30.0	36.3	32.1
Reserves for obsolescence [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		71.9	73.9	81.1
Expensed		18.4	16.0	12.0
Write-Offs and Other		22.8	18.0	19.2
Balance at End of Year		67.5	71.9	73.9
Reserve for royalty advances [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		93.8	90.1	86.8
Expensed		4.1	4.3	4.1
Write-Offs and Other		0.9	0.6	0.8
Balance at End of Year		$ 97.0	$ 93.8	$ 90.1

[1] Represents actual returns charged to the reserve