Fair Value Measurements (Details) - Schedule of non-financial assets measured and recorded at fair value on a non-recurring basis (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	5.00%	5.00%	5.00%
Impairment, Goodwill	$ 13.4	$ 0
Other Intangible Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additions due to acquisition	0	0.2
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0		0
Impairment, Investments	5.8		1.3
Property, plant and equipment, net	0	0	0.6
Impairment, Property, plant and equipment, net	7.6	5.2	4.0
Goodwill	0		2.7
Impairment, Goodwill	13.4		0
Prepublication assets	0	0	0
Impairment, Prepublication assets	5.7	2.0	0.8
Other intangible assets		0.3	5.4
Impairment, Other intangible assets		0	6.8
Other intangible assets impairment			4.9
Fair Value, Measurements, Nonrecurring [Member] | Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additions due to acquisition	1.0		0
Fair Value, Measurements, Nonrecurring [Member] | Property, Plant and Equipment, Net [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additions due to acquisition	0	0	0
Fair Value, Measurements, Nonrecurring [Member] | Goodwill [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additions due to acquisition	0		2.7
Fair Value, Measurements, Nonrecurring [Member] | Prepublication Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additions due to acquisition	0	0	0
Fair Value, Measurements, Nonrecurring [Member] | Other Intangible Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additions due to acquisition		0.3	5.4
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0		0
Property, plant and equipment, net	0	0	0
Goodwill	0		0
Prepublication assets	0	0	0
Other intangible assets		0	0
Other intangible assets impairment			0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0		0
Property, plant and equipment, net	0	0	0.6
Goodwill	0		2.7
Prepublication assets	0	0	0
Other intangible assets		0.3	5.4
Other intangible assets impairment			4.9
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0		0
Property, plant and equipment, net	0	0	0
Goodwill	0		0
Prepublication assets	0	0	0
Other intangible assets		0	0
Other intangible assets impairment			$ 0
Notes Due 2013 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	5.00%