Revenues - Disaggregation of Revenue Data (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2026	May 31, 2025	May 31, 2024
Disaggregation of Revenue [Line Items]
Revenues	$ 1,581.9	$ 1,625.5	$ 1,589.7
Rental income	7.2	11.2	9.7
Overhead
Disaggregation of Revenue [Line Items]
Revenues	7.2	11.2	9.7
Childrens Book Publishing And Distribution \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	964.2	963.9	953.3
Childrens Book Publishing And Distribution \| Trade \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	289.9	304.7	298.7
Childrens Book Publishing And Distribution \| Trade - International \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	41.2	46.7	50.3
Childrens Book Publishing And Distribution \| Book Clubs \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	57.1	64.2	62.7
Childrens Book Publishing And Distribution \| Book Fairs \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	576.0	548.3	541.6
Education \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	267.6	309.8	351.2
International \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	277.2	279.6	273.6
International \| Major Markets \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	235.9	241.6	228.6
International \| Other Markets \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	41.3	38.0	45.0
Entertainment \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	65.7	61.0	1.9
Entertainment \| Entertainment - U.S. \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	8.8	5.2	1.9
Entertainment \| Entertainment - International \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenues	$ 56.9	$ 55.8	$ 0.0