Revenues - Disaggregation of Revenue Data (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 1,642.9	$ 1,300.3	$ 1,487.1
Revenue Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Customer with over 10% of revenues		152.7
Revenue Benchmark | Customer Concentration Risk | Customer 1
Disaggregation of Revenue [Line Items]
Percentage of total revenues		12.00%
Childrens Book Publishing And Distribution
Disaggregation of Revenue [Line Items]
Revenues	946.5	$ 675.0	881.7
Childrens Book Publishing And Distribution | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	946.5	675.0	881.7
Childrens Book Publishing And Distribution | Trade
Disaggregation of Revenue [Line Items]
Revenues	344.0	328.8	306.7
Childrens Book Publishing And Distribution | Trade - International
Disaggregation of Revenue [Line Items]
Revenues	46.4	36.5	33.8
Childrens Book Publishing And Distribution | Book Clubs
Disaggregation of Revenue [Line Items]
Revenues	126.4	145.4	157.4
Childrens Book Publishing And Distribution | Book Fairs
Disaggregation of Revenue [Line Items]
Revenues	429.7	$ 164.3	383.8
Childrens Book Publishing And Distribution | Revenue Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Customer with over 10% of revenues		119.7
Education
Disaggregation of Revenue [Line Items]
Revenues	393.6	$ 312.3	287.3
Education | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	393.6	$ 312.3	287.3
Education | Revenue Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Customer with over 10% of revenues		8.8
International Segment
Disaggregation of Revenue [Line Items]
Revenues	302.8	$ 313.0	318.1
International Segment | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	302.8	313.0	318.1
International Segment | Major Markets
Disaggregation of Revenue [Line Items]
Revenues	237.1	226.8	227.1
International Segment | Other Markets
Disaggregation of Revenue [Line Items]
Revenues	$ 65.7	$ 86.2	$ 91.0
International Segment | Revenue Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Customer with over 10% of revenues		24.2