Segment Information (Details) - Schedule of segment reporting information $ in Millions		12 Months Ended
		May 31, 2018 USD ($) segment	May 31, 2017 USD ($)	May 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment		3
Revenues		$ 1,628.4	$ 1,741.6	$ 1,672.8
Bad debts		9.5	11.0	12.3
Depreciation and amortization	[1]	65.7	62.0	65.3
Asset impairments		11.2	6.8	14.4
Segment operating income (loss)		55.6	89.2	71.7
Segment assets		1,825.4	1,760.0	1,712.6
Goodwill		119.2	118.9	116.2
Expenditures for long-lived assets including royalty advances		197.6	151.4	95.8
Long-lived assets		820.0	719.4	672.8
Operating Segments [Member] | Children's Book Publishing and Distribution [Member]
Segment Reporting Information [Line Items]
Revenues	[2]	961.5	1,052.1	1,000.9
Bad debts	[2]	4.4	4.2	5.6
Depreciation and amortization	[1],[2]	21.7	22.5	26.5
Asset impairments	[2]	0.2	0.0	0.0
Segment operating income (loss)	[2]	105.6	143.1	120.6
Segment assets	[2]	426.6	395.7	394.4
Goodwill	[2]	40.9	40.9	40.9
Expenditures for long-lived assets including royalty advances	[2]	57.4	63.6	46.3
Long-lived assets	[2]	148.2	140.2	144.4
Operating Segments [Member] | Education [Member]
Segment Reporting Information [Line Items]
Revenues	[2]	297.3	312.7	299.7
Bad debts	[2]	1.4	1.1	1.8
Depreciation and amortization	[1],[2]	9.0	8.5	11.8
Asset impairments	[2]	0.0	1.1	6.9
Segment operating income (loss)	[2]	34.1	50.7	42.8
Segment assets	[2]	210.6	200.6	172.8
Goodwill	[2]	68.3	68.0	65.4
Expenditures for long-lived assets including royalty advances	[2]	20.4	21.8	9.1
Long-lived assets	[2]	104.8	93.9	82.6
Operating Segments [Member] | Overhead [Member]
Segment Reporting Information [Line Items]
Revenues	[2],[3]	0.0	0.0	0.0
Bad debts	[2],[3]	0.0	0.0	0.0
Depreciation and amortization	[1],[2],[3]	28.8	23.6	19.0
Asset impairments	[2],[3]	11.0	5.7	7.5
Segment operating income (loss)	[2],[3]	(101.8)	(124.3)	(104.2)
Segment assets	[2],[3]	927.9	922.2	898.0
Goodwill	[2],[3]	0.0	0.0	0.0
Expenditures for long-lived assets including royalty advances	[2],[3]	104.5	54.5	26.6
Long-lived assets	[2],[3]	492.7	418.2	379.2
Operating Segments [Member] | Total Domestic [Member]
Segment Reporting Information [Line Items]
Revenues		1,258.8	1,364.8	1,300.6
Bad debts		5.8	5.3	7.4
Depreciation and amortization	[1]	59.5	54.6	57.3
Asset impairments		11.2	6.8	14.4
Segment operating income (loss)		37.9	69.5	59.2
Segment assets		1,565.1	1,518.5	1,465.2
Goodwill		109.2	108.9	106.3
Expenditures for long-lived assets including royalty advances		182.3	139.9	82.0
Long-lived assets		745.7	652.3	606.2
Operating Segments [Member] | International [Member]
Segment Reporting Information [Line Items]
Revenues	[2]	369.6	376.8	372.2
Bad debts	[2]	3.7	5.7	4.9
Depreciation and amortization	[1],[2]	6.2	7.4	8.0
Asset impairments	[2]	0.0	0.0	0.0
Segment operating income (loss)	[2]	17.7	19.7	12.5
Segment assets	[2]	260.3	241.5	247.4
Goodwill	[2]	10.0	10.0	9.9
Expenditures for long-lived assets including royalty advances	[2]	15.3	11.5	13.8
Long-lived assets	[2]	74.3	67.1	66.6
Expenditures for long-lived assets	[2]	10.0	6.7	10.3
Long-lived assets	[2]	$ 36.8	$ 33.4	$ 35.3

[1] Other non-current assets include property, plant and equipment, prepublication assets, production assets, royalty advances, goodwill, intangible assets and investments. Expenditures for other non-current assets for the International reportable segment include expenditures for long-lived assets of $10.0, $6.7 and $10.3 for the fiscal years ended May 31, 2018, 2017 and 2016, respectively. Other non-current assets for the International reportable segment include long-lived assets of $36.8, $33.4 and $35.3 at May 31, 2018, 2017 and 2016, respectively.

[2] 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 Connectic

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