Asset Write Down (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	May 31, 2024	May 31, 2023	May 31, 2022
Asset Write Down [Line Items]
Asset impairments and write downs	$ 10.0	$ 0.0	$ 0.4
Operating lease, impairment loss	3.9
Operating lease right-of-use assets, net	99.1	85.7
Assets held for sale			3.7
Gain (Loss) on assets held for sale	$ 0.0	$ 0.0	$ (15.1)
Loss on assets held for sale, impact on earnings per share, basic	$ 0.25		$ 0.33
Loss on assets held for sale, impact on earnings per share, diluted	$ 0.25		$ 0.32
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]	Asset impairments and write downs
Education Solutions
Asset Write Down [Line Items]
Asset impairments and write downs	$ 6.1
Overhead
Asset Write Down [Line Items]
Operating lease right-of-use assets, net	2.3
International
Asset Write Down [Line Items]
Operating lease right-of-use assets, net	1.1
Children's Book Publishing and Distribution
Asset Write Down [Line Items]
Operating lease right-of-use assets, net	$ 0.5