Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 324.9	$ 344.5	$ 1,175.7	$ 1,128.5
Children's Book Publishing & Distribution
Disaggregation of Revenue [Line Items]
Revenues	204.0	201.0	747.0	669.3
Children's Book Publishing & Distribution | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	204.0	201.0	747.0	669.3
Children's Book Publishing & Distribution | Book Clubs - U.S.
Disaggregation of Revenue [Line Items]
Revenues	27.7	40.5	91.6	99.2
Children's Book Publishing & Distribution | Book Fairs - U.S.
Disaggregation of Revenue [Line Items]
Revenues	103.5	76.0	372.6	268.2
Children's Book Publishing & Distribution | Trade - U.S.
Disaggregation of Revenue [Line Items]
Revenues	64.8	77.1	248.9	266.6
Children's Book Publishing & Distribution | Trade - International
Disaggregation of Revenue [Line Items]
Revenues	8.0	7.4	33.9	35.3
Education
Disaggregation of Revenue [Line Items]
Revenues	70.0	77.2	223.2	236.8
Education | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	70.0	77.2	223.2	236.8
International
Disaggregation of Revenue [Line Items]
Revenues	50.9	66.3	205.5	222.4
International | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	50.9	66.3	205.5	222.4
International | Major Markets
Disaggregation of Revenue [Line Items]
Revenues	41.3	48.8	171.8	175.1
International | Other Markets
Disaggregation of Revenue [Line Items]
Revenues	$ 9.6	$ 17.5	$ 33.7	$ 47.3