Goodwill and Intangible Assets - Schedule of Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Feb. 28, 2014	May 31, 2013
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 1,064,868	$ 1,044,222
Other intangible assets	702,818	691,508
Less accumulated amortization	338,305	290,660
Other intangible assets, net	364,513	400,848
Customer-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	566,680	559,884
Less accumulated amortization	301,974	262,649
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	6,004	6,390
Less accumulated amortization	4,023	3,967
Acquired Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	15,000	15,000
Less accumulated amortization	2,652	1,248
Contract-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	115,134	110,234
Less accumulated amortization	$ 29,656	$ 22,796