Description of the Business, Basis of Presentation and Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2012 tax_jurisdiction
Property, Plant and Equipment [Line Items]
Number of Countries in which Entity Operates	150
Restricted Cash (in Dollars)	$ 300,000	$ 1,000,000
Capitalized computer software, net (in Dollars)	33,400,000	50,700,000
Capitalized computer software, amortization expense (in Dollars)	28,800,000	31,200,000	27,600,000
Payments to acquire building	253,900,000	0	0
Prepublication costs (in excess of)	1,000,000
Accrual for taxes other than income taxes (in Dollars)		19,700,000
Number of tax jurisdictions			2
Payments of taxes other than income taxes		15,300,000
Settlement	1,700,000
Deferred advertising costs (in Dollars)	4,600,000	4,500,000
Building [Member]
Property, Plant and Equipment [Line Items]
Depreciable life	40 years
Payments to acquire real estate	255,700,000
Payments to acquire building	253,900,000
Capitalized Software [Member]
Property, Plant and Equipment [Line Items]
Impairment of capitalized software	$ 7,600,000
Capitalized Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Depreciable life	3 years
Capitalized Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Depreciable life	7 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Depreciable life	10 years