Segment Information (Details) - Schedule of segment reporting information (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Feb. 28, 2015		Feb. 28, 2014		Feb. 28, 2015		Feb. 28, 2014		May 31, 2014	May 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 382.1		$ 373.5		$ 1,331.5		$ 1,273.0
Bad debt expense	3.2		2.5		9.6		6.4
Depreciation & Amortization, including prepublication and production costs	26.4		29.6		82.8	[1]	89.3	[1]
Asset impairments	0		0		2.9	[2]	13.4	[2]
Segment operating income (loss)	(35.2)		(34.3)		24.2		14.5
Segment assets	1,551.1		1,587.5		1,551.1		1,587.5
Goodwill	144.4		144.5		144.4		144.5		144.5	157.9
Expenditures for long-lived assets including royalty advances	30.1		280.3		86.2		339.4
Long-lived assets	808.5		850.5		808.5		850.5
Children's Book Publishing and Distribution
Segment Reporting Information [Line Items]
Revenues	202.9	[3]	190.0	[3]	660.2		596.7
Bad debt expense	1.6	[3]	0.2	[3]	4.3		1.6
Depreciation & Amortization, including prepublication and production costs	7.4	[2],[3]	7.8	[2],[3]	23.5	[1]	23.6	[1]
Asset impairments					0	[2]	13.4	[2]
Segment operating income (loss)	(2.2)	[3]	(10.6)	[3]	45.6		(3.2)
Segment assets	441.8		442.2		441.8		442.2
Goodwill	40.9		40.9		40.9		40.9
Expenditures for long-lived assets including royalty advances	9.9	[3]	8.9	[3]	35.4		30.8
Long-lived assets	143.0		145.8		143.0		145.8
Educational Technology and Services
Segment Reporting Information [Line Items]
Revenues	34.3		35.8		174.6		191.5
Bad debt expense	0.4		0.4		0.7		0.8
Depreciation & Amortization, including prepublication and production costs	7.7	[2]	7.1	[2]	23.0	[1]	21.0	[1]
Asset impairments					0	[2]	0	[2]
Segment operating income (loss)	(12.4)		(10.7)		16.7		32.4
Segment assets	160.5		162.1		160.5		162.1
Goodwill	22.7		22.7		22.7		22.7
Expenditures for long-lived assets including royalty advances	9.1		7.1		22.6		22.9
Long-lived assets	119.6		118.1		119.6		118.1
Classroom and Supplemental Materials Publishing
Segment Reporting Information [Line Items]
Revenues	49.1		46.0		156.7		144.7
Bad debt expense	0.5		0.4		1.3		1.0
Depreciation & Amortization, including prepublication and production costs	2.7	[2]	2.7	[2]	8.5	[1]	7.8	[1]
Asset impairments					0	[2]	0	[2]
Segment operating income (loss)	3.4		2.1		15.2		11.8
Segment assets	146.5		145.1		146.5		145.1
Goodwill	65.4		65.4		65.4		65.4
Expenditures for long-lived assets including royalty advances	1.8		2.3		5.0		6.9
Long-lived assets	87.9		89.9		87.9		89.9
Media, Licensing and Advertising
Segment Reporting Information [Line Items]
Revenues	9.5	[3]	10.7	[3]	34.6		34.8
Bad debt expense	0	[3]	0.1	[3]	0.1		0.2
Depreciation & Amortization, including prepublication and production costs	1.4	[2],[3]	1.4	[2],[3]	4.9	[1]	2.5	[1]
Asset impairments					0	[2]	0	[2]
Segment operating income (loss)	(2.0)	[3]	(2.3)	[3]	(6.2)		(5.2)
Segment assets	26.7		26.5		26.7		26.5
Goodwill	5.4		5.4		5.4		5.4
Expenditures for long-lived assets including royalty advances	1.2	[3]	2.6	[3]	4.6		6.2
Long-lived assets	13.7		15.2		13.7		15.2
Overhead
Segment Reporting Information [Line Items]
Revenues	0	[1],[3]	0	[1],[3]	0	[3]	0	[3]
Bad debt expense	0	[1],[3]	0	[1],[3]	0	[3]	0	[3]
Depreciation & Amortization, including prepublication and production costs	5.1	[1],[2],[3]	8.7	[1],[2],[3]	16.3	[1],[3]	29.2	[1],[3]
Asset impairments					2.9	[2],[3]	0	[2],[3]
Segment operating income (loss)	(22.9)	[1],[3]	(12.9)	[1],[3]	(66.0)	[3]	(42.9)	[3]
Segment assets	524.4	[3]	558.7	[3]	524.4	[3]	558.7	[3]
Goodwill	0	[3]	0	[3]	0	[3]	0	[3]
Expenditures for long-lived assets including royalty advances	4.4	[1],[3]	256.8	[1],[3]	8.2	[3]	264.8	[3]
Long-lived assets	380.2	[3]	418.8	[3]	380.2	[3]	418.8	[3]
Total Domestic
Segment Reporting Information [Line Items]
Revenues	295.8		282.5		1,026.1		967.7
Bad debt expense	2.5		1.1		6.4		3.6
Depreciation & Amortization, including prepublication and production costs	24.3		27.7		76.2	[1]	84.1	[1]
Asset impairments					2.9	[2]	13.4	[2]
Segment operating income (loss)	(36.1)		(34.4)		5.3		(7.1)
Segment assets	1,299.9		1,334.6		1,299.9		1,334.6
Goodwill	134.4		134.4		134.4		134.4
Expenditures for long-lived assets including royalty advances	26.4		277.7		75.8		331.6
Long-lived assets	744.4		787.8		744.4		787.8
International Segment
Segment Reporting Information [Line Items]
Revenues	86.3		91.0		305.4		305.3
Bad debt expense	0.7		1.4		3.2		2.8
Depreciation & Amortization, including prepublication and production costs	2.1	[2]	1.9	[2]	6.6	[1]	5.2	[1]
Asset impairments					0	[2]	0	[2]
Segment operating income (loss)	0.9		0.1		18.9		21.6
Segment assets	251.2		252.9		251.2		252.9
Goodwill	10.0		10.1		10.0		10.1
Expenditures for long-lived assets including royalty advances	3.7		2.6		10.4		7.8
Long-lived assets	$ 64.1		$ 62.7		$ 64.1		$ 62.7

[1] Includes depreciation of property, plant and equipment and amortization of intangible assets, and prepublication and production costs.

[2] Includes an asset impairment related to the closure of a retail store in New York City in fiscal 2015 and an impairment of goodwill attributable to legacy acquisitions associated with the book club operations in the Children’s Book Publishing and Distribution segment in fiscal 2014.

[3] Overhead includes all domestic corporate amounts not allocated to segments, including expenses and costs related to the management of corporate assets. Unallocated assets are principally comprised of deferred income taxes and property, plant and equipment related to the Company’s headquarters in the metropolitan New York area, its fulfillment and distribution facilities located in Missouri and its facility located in Connecticut.