Segment Information (Detail) - Schedule of segment reporting information (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Feb. 28, 2013		Feb. 29, 2012		Feb. 28, 2013		Feb. 29, 2012		May 31, 2012	May 31, 2011
Revenues	$ 380.5		$ 467.0		$ 1,290.3		$ 1,470.3
Bad debt expense	(0.6)		3.1		3.9		7.8
Depreciation and amortization	16.5	[1]	16.0	[1]	49.3	[1]	46.6	[1]
Amortization	12.7	[2]	12.0	[2]	36.5	[2]	36.4	[2]
Loss on leases and asset impairments			0.8				7.0
Segment operating income (loss)	(27.7)		(11.9)		25.7		94.9
Segment assets	1,646.5		1,636.9		1,646.5		1,636.9
Goodwill	158.0		162.9		158.0		162.9		157.7	154.2
Expenditures for long-lived assets including royalty advances	38.0		39.1		113.3		96.4
Long-lived assets	695.7		690.6		695.7		690.6
Children's Book Publishing and Distribution [Member]
Revenues	189.4	[3],[4]	268.8	[3],[4]	610.6	[3],[4]	739.3	[3],[4]
Bad debt expense	(1.6)	[3],[4]	1.6	[3],[4]		[3],[4]	3.2	[3],[4]
Depreciation and amortization	4.0	[1],[3],[4]	4.4	[1],[3],[4]	12.1	[1],[3],[4]	11.9	[1],[3],[4]
Amortization	3.7	[2],[3],[4]	2.8	[2],[3],[4]	11.0	[2],[3],[4]	9.0	[2],[3],[4]
Loss on leases and asset impairments		[3],[4]	0.5	[3],[4]		[3],[4]	0.5	[3],[4]
Segment operating income (loss)	(10.1)	[3],[4]	12.2	[3],[4]	3.6	[3],[4]	70.7	[3],[4]
Segment assets	549.0	[3],[4]	597.1	[3],[4]	549.0	[3],[4]	597.1	[3],[4]
Goodwill	54.3	[3],[4]	54.3	[3],[4]	54.3	[3],[4]	54.3	[3],[4]
Expenditures for long-lived assets including royalty advances	11.9	[3],[4]	11.7	[3],[4]	39.1	[3],[4]	32.8	[3],[4]
Long-lived assets	170.2	[3],[4]	173.7	[3],[4]	170.2	[3],[4]	173.7	[3],[4]
Educational Technology and Services [Member]
Revenues	41.8	[3]	40.0	[3]	174.0	[3]	202.0	[3]
Bad debt expense	0.5	[3]	0.3	[3]	0.6	[3]	1.0	[3]
Depreciation and amortization	0.3	[1],[3]	0.2	[1],[3]	0.9	[1],[3]	0.9	[1],[3]
Amortization	5.5	[2],[3]	5.3	[2],[3]	16.2	[2],[3]	15.6	[2],[3]
Loss on leases and asset impairments		[3]		[3]		[3]		[3]
Segment operating income (loss)	(3.5)	[3]	(5.9)	[3]	26.6	[3]	47.5	[3]
Segment assets	177.1	[3]	156.6	[3]	177.1	[3]	156.6	[3]
Goodwill	22.7	[3]	22.7	[3]	22.7	[3]	22.7	[3]
Expenditures for long-lived assets including royalty advances	10.6	[3]	6.7	[3]	28.0	[3]	18.0	[3]
Long-lived assets	111.8	[3]	98.5	[3]	111.8	[3]	98.5	[3]
Classroom Supplemental Materials Publishing [Member]
Revenues	43.2	[3]	38.2	[3]	134.3	[3]	142.6	[3]
Bad debt expense		[3]	0.4	[3]	1.2	[3]	1.3	[3]
Depreciation and amortization	0.3	[1],[3]	0.3	[1],[3]	1.0	[1],[3]	0.8	[1],[3]
Amortization	2.1	[2],[3]	1.8	[2],[3]	5.7	[2],[3]	4.9	[2],[3]
Loss on leases and asset impairments		[3]		[3]		[3]		[3]
Segment operating income (loss)	(0.2)	[3]	(3.4)	[3]	4.6	[3]	9.0	[3]
Segment assets	159.9	[3]	153.3	[3]	159.9	[3]	153.3	[3]
Goodwill	65.4	[3]	70.5	[3]	65.4	[3]	70.5	[3]
Expenditures for long-lived assets including royalty advances	2.7	[3]	4.9	[3]	6.9	[3]	9.3	[3]
Long-lived assets	90.2	[3]	88.3	[3]	90.2	[3]	88.3	[3]
Media, Licensing and Advertising [Member]
Revenues	11.7	[3],[4]	14.4	[3],[4]	43.1	[3],[4]	49.0	[3],[4]
Bad debt expense		[3],[4]		[3],[4]		[3],[4]		[3],[4]
Depreciation and amortization	0.1	[1],[3],[4]		[1],[3],[4]	0.3	[1],[3],[4]	0.4	[1],[3],[4]
Amortization	1.0	[2],[3],[4]	1.5	[2],[3],[4]	2.3	[2],[3],[4]	5.1	[2],[3],[4]
Loss on leases and asset impairments		[3],[4]		[3],[4]		[3],[4]		[3],[4]
Segment operating income (loss)	(2.3)	[3],[4]	(1.2)	[3],[4]	(0.9)	[3],[4]	(3.3)	[3],[4]
Segment assets	27.2	[3],[4]	38.2	[3],[4]	27.2	[3],[4]	38.2	[3],[4]
Goodwill	5.4	[3],[4]	5.4	[3],[4]	5.4	[3],[4]	5.4	[3],[4]
Expenditures for long-lived assets including royalty advances	1.7	[3],[4]	1.3	[3],[4]	4.8	[3],[4]	5.3	[3],[4]
Long-lived assets	13.6	[3],[4]	19.7	[3],[4]	13.6	[3],[4]	19.7	[3],[4]
Overhead [Member]
Revenues		[3],[5]		[3],[5]		[3],[5]		[3],[5]
Bad debt expense		[3],[5]		[3],[5]		[3],[5]		[3],[5]
Depreciation and amortization	10.3	[1],[3],[5]	9.1	[1],[3],[5]	31.0	[1],[3],[5]	27.7	[1],[3],[5]
Amortization		[2],[3],[5]		[2],[3],[5]		[2],[3],[5]		[2],[3],[5]
Loss on leases and asset impairments		[3],[5]		[3],[5]		[3],[5]	6.2	[3],[5]
Segment operating income (loss)	(13.6)	[3],[5]	(17.9)	[3],[5]	(37.7)	[3],[5]	(59.8)	[3],[5]
Segment assets	434.4	[3],[5]	397.4	[3],[5]	434.4	[3],[5]	397.4	[3],[5]
Goodwill		[3],[5]		[3],[5]		[3],[5]		[3],[5]
Expenditures for long-lived assets including royalty advances	7.6	[3],[5]	9.4	[3],[5]	25.9	[3],[5]	22.0	[3],[5]
Long-lived assets	241.5	[3],[5]	242.8	[3],[5]	241.5	[3],[5]	242.8	[3],[5]
Total Domestic [Member]
Revenues	286.1		361.4		962.0		1,132.9
Bad debt expense	(1.1)		2.3		1.8		5.5
Depreciation and amortization	15.0	[1]	14.0	[1]	45.3	[1]	41.7	[1]
Amortization	12.3	[2]	11.4	[2]	35.2	[2]	34.6	[2]
Loss on leases and asset impairments			0.5				6.7
Segment operating income (loss)	(29.7)		(16.2)		(3.8)		64.1
Segment assets	1,347.6		1,342.6		1,347.6		1,342.6
Goodwill	147.8		152.9		147.8		152.9
Expenditures for long-lived assets including royalty advances	34.5		34.0		104.7		87.4
Long-lived assets	627.3		623.0		627.3		623.0
International Segment [Member]
Revenues	94.4	[3]	105.6	[3]	328.3	[3]	337.4	[3]
Bad debt expense	0.5	[3]	0.8	[3]	2.1	[3]	2.3	[3]
Depreciation and amortization	1.5	[1],[3]	2.0	[1],[3]	4.0	[1],[3]	4.9	[1],[3]
Amortization	0.4	[2],[3]	0.6	[2],[3]	1.3	[2],[3]	1.8	[2],[3]
Loss on leases and asset impairments		[3]	0.3	[3]		[3]	0.3	[3]
Segment operating income (loss)	2.0	[3]	4.3	[3]	29.5	[3]	30.8	[3]
Segment assets	298.9	[3]	294.3	[3]	298.9	[3]	294.3	[3]
Goodwill	10.2	[3]	10.0	[3]	10.2	[3]	10.0	[3]
Expenditures for long-lived assets including royalty advances	3.5	[3]	5.1	[3]	8.6	[3]	9.0	[3]
Long-lived assets	$ 68.4	[3]	$ 67.6	[3]	$ 68.4	[3]	$ 67.6	[3]

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

[2] Includes amortization of prepublication and production costs.

[3] As discussed under "Discontinued Operations" in Note 1, "Basis of Presentation," the Company closed or sold several operations during fiscal 2009, fiscal 2010 and fiscal 2012, and presently holds for sale one facility. All of these businesses are classified as discontinued operations in the Company's financial statements and, as such, are not reflected in this table.

[4] As discussed under "Segment" in Note 1, a business previously reported in the Media, Licensing and Advertising segment is now included in the Children's Book Publishing and Distribution segment.

[5] 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.