Revenues - Deferred Revenue (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Disaggregation of Revenue [Line Items]
Total deferred revenue	$ 172.8	$ 99.1
Book fairs incentive credits
Disaggregation of Revenue [Line Items]
Total deferred revenue	100.1	59.9
Magazines+ subscriptions
Disaggregation of Revenue [Line Items]
Total deferred revenue	4.5	4.6
U.S. digital subscriptions
Disaggregation of Revenue [Line Items]
Total deferred revenue	19.5	11.9
U.S. education related
Disaggregation of Revenue [Line Items]
Total deferred revenue	13.6	6.2
Media-related
Disaggregation of Revenue [Line Items]
Total deferred revenue	15.8	2.5
Stored value cards
Disaggregation of Revenue [Line Items]
Total deferred revenue	9.4	2.9
Other
Disaggregation of Revenue [Line Items]
Total deferred revenue	$ 9.9	$ 11.1