Revenues - Deferred Revenue (Details) - USD ($) $ in Millions	May 31, 2024	May 31, 2023
Disaggregation of Revenue [Line Items]
Total contract liabilities	$ 167.6	$ 169.1
Book fairs incentive credits
Disaggregation of Revenue [Line Items]
Total contract liabilities	114.2	110.8
Magazines+ subscriptions
Disaggregation of Revenue [Line Items]
Total contract liabilities	4.6	5.0
U.S. digital subscriptions
Disaggregation of Revenue [Line Items]
Total contract liabilities	15.6	22.8
U.S. education related
Disaggregation of Revenue [Line Items]
Total contract liabilities	10.1	9.8
Stored value programs
Disaggregation of Revenue [Line Items]
Total contract liabilities	16.7	12.4
Other
Disaggregation of Revenue [Line Items]
Total contract liabilities	$ 6.4	$ 8.3