Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2022	Aug. 31, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 262.9	$ 259.8
Children's Book Publishing and Distribution
Disaggregation of Revenue [Line Items]
Revenues	124.7	115.8
Children's Book Publishing and Distribution | Book Clubs - U.S.
Disaggregation of Revenue [Line Items]
Revenues	6.3	6.8
Children's Book Publishing and Distribution | Book Fairs - U.S.
Disaggregation of Revenue [Line Items]
Revenues	28.3	16.0
Children's Book Publishing and Distribution | Trade - U.S.
Disaggregation of Revenue [Line Items]
Revenues	76.2	80.1
Children's Book Publishing and Distribution | Trade - International
Disaggregation of Revenue [Line Items]
Revenues	13.9	12.9
Education
Disaggregation of Revenue [Line Items]
Revenues	73.2	80.1
International
Disaggregation of Revenue [Line Items]
Revenues	65.0	63.9
International | Major Markets
Disaggregation of Revenue [Line Items]
Revenues	53.4	47.5
International | Other Markets
Disaggregation of Revenue [Line Items]
Revenues	$ 11.6	$ 16.4