Goodwill and Other Intangible Assets - Schedule of Intangible Assets (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 31, 2013	May 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 5,309.6
Gross Carrying Amount	5,358.7
Impairment Charge	(145.1)
New Carrying Amount	5,213.6
Accumulated Amortization	(1,634.1)	(1,870.0)
Impairment Charge	50.7
Net Carrying Amount	3,630.2	3,439.6
Core technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		1,743.3
Gross Carrying Amount	1,772.6
Impairment Charge	(39.0)
New Carrying Amount	1,733.6
Accumulated Amortization	(481.1)	(569.8)
Impairment Charge	4.1
Net Carrying Amount	1,256.6	1,173.5
Completed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		672.0
Gross Carrying Amount	628.8
Impairment Charge	(48.5)
New Carrying Amount	580.3
Accumulated Amortization	(254.9)	(262.1)
Impairment Charge	36.7
Net Carrying Amount	362.1	409.9
Product trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		208.1
Gross Carrying Amount	204.2
Impairment Charge	0
New Carrying Amount	204.2
Accumulated Amortization	(65.9)	(77.6)
Impairment Charge	0
Net Carrying Amount	138.3	130.5
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		2,371.6
Gross Carrying Amount	2,429.5
Impairment Charge	(46.1)
New Carrying Amount	2,383.4
Accumulated Amortization	(828.4)	(955.9)
Impairment Charge	9.9
Net Carrying Amount	1,564.9	1,415.7
Non-compete contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		4.9
Gross Carrying Amount	4.6
Impairment Charge	0
New Carrying Amount	4.6
Accumulated Amortization	(3.8)	(4.6)
Impairment Charge	0
Net Carrying Amount	0.8	0.3
Sub-total [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		4,999.9
Gross Carrying Amount	5,039.7
Impairment Charge	(133.6)
New Carrying Amount	4,906.1
Accumulated Amortization	(1,634.1)	(1,870.0)
Impairment Charge	50.7
Net Carrying Amount	3,322.7	3,129.9
Corporate trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		309.7
Gross Carrying Amount	319.0
Impairment Charge	(11.5)
New Carrying Amount	307.5
Accumulated Amortization	0	0
Impairment Charge	0
Net Carrying Amount	$ 307.5	$ 309.7