Segment Information (Details) - Schedule of segment reporting information $ in Millions		12 Months Ended
		May 31, 2017 USD ($) segment	May 31, 2016 USD ($)	May 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment		3
Revenues		$ 1,741.6	$ 1,672.8	$ 1,635.8
Bad debts		11.0	12.3	10.6
Depreciation and amortization	[1]	62.0	65.3	78.3
Asset impairments		6.8	14.4	15.8
Segment operating income (loss)		88.9	67.6	32.9
Segment assets		1,760.0	1,712.6	1,819.2
Goodwill		118.9	116.2	116.3
Expenditures for long-lived assets including royalty advances	[2]	151.4	95.8	95.5
Long-lived assets		719.4	672.8	680.1
Operating Segments [Member] | Children's Book Publishing and Distribution [Member]
Segment Reporting Information [Line Items]
Revenues	[3]	1,052.1	1,000.9	957.8
Bad debts	[3]	4.2	5.6	5.3
Depreciation and amortization	[1],[3]	22.5	26.5	35.4
Asset impairments	[3]	0.0	0.0	10.2
Segment operating income (loss)	[3]	143.1	120.6	94.6
Segment assets	[3]	395.7	394.4	378.3
Goodwill	[3]	40.9	40.9	40.9
Expenditures for long-lived assets including royalty advances	[2],[3]	63.6	46.3	51.7
Long-lived assets	[3]	140.2	144.4	140.2
Operating Segments [Member] | Education [Member]
Segment Reporting Information [Line Items]
Revenues	[3]	312.7	299.7	276.8
Bad debts	[3]	1.1	1.8	1.9
Depreciation and amortization	[1],[3]	8.5	11.8	13.2
Asset impairments	[3]	1.1	6.9	0.0
Segment operating income (loss)	[3]	50.7	42.8	39.4
Segment assets	[3]	200.6	172.8	178.3
Goodwill	[3]	68.0	65.4	65.4
Expenditures for long-lived assets including royalty advances	[2],[3]	21.8	9.1	11.1
Long-lived assets	[3]	93.9	82.6	92.9
Operating Segments [Member] | Overhead [Member]
Segment Reporting Information [Line Items]
Revenues	[3],[4]	0.0	0.0	0.0
Bad debts	[3],[4]	0.0	0.0	0.0
Depreciation and amortization	[1],[3],[4]	23.6	19.0	21.3
Asset impairments	[3],[4]	5.7	7.5	2.9
Segment operating income (loss)	[3],[4]	(123.6)	(107.2)	(121.7)
Segment assets	[3],[4]	922.2	898.0	1,014.6
Goodwill	[3],[4]	0.0	0.0	0.0
Expenditures for long-lived assets including royalty advances	[2],[3],[4]	54.5	26.6	11.6
Long-lived assets	[3],[4]	418.2	379.2	378.5
Operating Segments [Member] | Total Domestic [Member]
Segment Reporting Information [Line Items]
Revenues		1,364.8	1,300.6	1,234.6
Bad debts		5.3	7.4	7.2
Depreciation and amortization	[1]	54.6	57.3	69.9
Asset impairments		6.8	14.4	13.1
Segment operating income (loss)		70.2	56.2	12.3
Segment assets		1,518.5	1,465.2	1,571.2
Goodwill		108.9	106.3	106.3
Expenditures for long-lived assets including royalty advances	[2]	139.9	82.0	74.4
Long-lived assets		652.3	606.2	611.6
Operating Segments [Member] | International [Member]
Segment Reporting Information [Line Items]
Revenues	[3]	376.8	372.2	401.2
Bad debts	[3]	5.7	4.9	3.4
Depreciation and amortization	[1],[3]	7.4	8.0	8.4
Asset impairments	[3]	0.0	0.0	2.7
Segment operating income (loss)	[3]	18.7	11.4	20.6
Segment assets	[3]	241.5	247.4	248.0
Goodwill	[3]	10.0	9.9	10.0
Expenditures for long-lived assets including royalty advances	[2],[3]	11.5	13.8	21.1
Long-lived assets	[3]	67.1	66.6	68.5
Expenditures for long-lived assets	[2],[3]	6.7	10.3	9.6
Long-lived assets	[3]	$ 33.4	$ 35.3	$ 37.3

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

[2] Other non-current assets include property, plant and equipment, prepublication, production, royalty advances, goodwill, intangibles and investments

[3] As discussed in Note 2, “Discontinued Operations,” the Company closed or sold several operations during the fourth quarter of fiscal 2015. 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] Overhead includes all domestic corporate amounts not allocated to operating 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, its facility located in Connecticut and unabsorbed burden associated with the former educational technology and services business.