Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2025	Feb. 29, 2024	Feb. 28, 2025	Feb. 29, 2024
Disaggregation of Revenue [Line Items]
Revenues	$ 335.4	$ 323.7	$ 1,117.2	$ 1,114.8
Corporate, Non-Segment
Disaggregation of Revenue [Line Items]
Revenues	2.8	2.5	8.4	7.3
Total Children's Book Publishing and Distribution | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	203.3	193.1	675.7	687.9
Total Children's Book Publishing and Distribution | Operating Segments | Book Clubs - U.S.
Disaggregation of Revenue [Line Items]
Revenues	15.2	13.3	51.1	48.3
Total Children's Book Publishing and Distribution | Operating Segments | Book Fairs - U.S.
Disaggregation of Revenue [Line Items]
Revenues	110.7	102.7	370.5	372.1
Total Children's Book Publishing and Distribution | Operating Segments | Trade - U.S.
Disaggregation of Revenue [Line Items]
Revenues	68.9	69.5	218.1	232.2
Total Children's Book Publishing and Distribution | Operating Segments | Trade - International
Disaggregation of Revenue [Line Items]
Revenues	8.5	7.6	36.0	35.3
Total Education Solutions | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	57.2	68.5	184.1	215.5
Total Entertainment | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	12.8	0.5	46.2	1.3
Total Entertainment | Operating Segments | Entertainment - U.S.
Disaggregation of Revenue [Line Items]
Revenues	1.0	0.5	3.9	1.3
Total Entertainment | Operating Segments | Entertainment - International
Disaggregation of Revenue [Line Items]
Revenues	11.8	0.0	42.3	0.0
Total International | Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	59.3	59.1	202.8	202.8
Total International | Operating Segments | Major Markets
Disaggregation of Revenue [Line Items]
Revenues	49.7	48.0	173.4	171.2
Total International | Operating Segments | Other Markets
Disaggregation of Revenue [Line Items]
Revenues	$ 9.6	$ 11.1	$ 29.4	$ 31.6