Fair Value Measurements (Details) - Schedule of non-financial assets measured and recorded at fair value on a non-recurring basis - USD ($) $ in Millions	12 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additions	$ 3.3	$ 7.0
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, plant and equipment, net	0.0	0.0	$ 0.0
Impairment, Property, plant and equipment, net	11.2	5.7	7.5
Goodwill		2.8
Impairment, Goodwill		0.0
Prepublication assets		0.0	0.0
Impairment, Prepublication assets		1.1	6.9
Intangible assets	0.0	6.8	1.9
Impairment, Intangible assets	0.0	0.0	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	0.0	0.0	0.0
Fair Value, Measurements, Nonrecurring [Member] | Goodwill [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additions		2.8
Fair Value, Measurements, Nonrecurring [Member] | Prepublication Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additions		0.0	0.0
Fair Value, Measurements, Nonrecurring [Member] | Other Intangible Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Intangible assets acquired	3.3	7.0	2.4
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, plant and equipment, net	0.0	0.0	0.0
Goodwill		0.0
Prepublication assets		0.0	0.0
Intangible assets	0.0	0.0	0.0
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, plant and equipment, net	0.0	0.0	0.0
Goodwill		0.0
Prepublication assets		0.0	0.0
Intangible assets	0.0	0.0	0.0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, plant and equipment, net	0.0	0.0	0.0
Goodwill		2.8
Prepublication assets		0.0	0.0
Intangible assets	$ 0.0	$ 7.0	$ 2.4