Fair Value Measurements - Schedule of non-financial assets measured and recorded at fair value on a non-recurring basis (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2024	May 31, 2023	May 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairments and write downs	$ 10.0	$ 0.0	$ 0.4
Fair Value, Nonrecurring | Prepublication assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	0.0
Asset impairments and write downs	3.0
Fair value of assets acquired	0.0
Fair Value, Nonrecurring | Operating lease right-of-use assets, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	0.0		0.0
Asset impairments and write downs	3.9		0.4
Fair value of assets acquired	0.0		0.0
Fair Value, Nonrecurring | Goodwill
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV		7.6
Asset impairments and write downs		0.0
Fair value of assets acquired		7.6
Fair Value, Nonrecurring | Intangible assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	5.5	3.6
Asset impairments and write downs	3.1	0.0
Fair value of assets acquired	6.0	4.1
Fair Value, Nonrecurring | Accounts Receivable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			1.4
Asset impairments and write downs			9.3
Fair value of assets acquired			0.0
Fair Value, Nonrecurring | Inventory
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			2.3
Asset impairments and write downs			1.6
Fair value of assets acquired			0.0
Fair Value, Nonrecurring | Other Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			0.0
Asset impairments and write downs			0.7
Fair value of assets acquired			0.0
Fair Value, Nonrecurring | Level 1 | Prepublication assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	0.0
Fair Value, Nonrecurring | Level 1 | Operating lease right-of-use assets, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	0.0		0.0
Fair Value, Nonrecurring | Level 1 | Goodwill
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV		0.0
Fair Value, Nonrecurring | Level 1 | Intangible assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	0.0	0.0
Fair Value, Nonrecurring | Level 1 | Accounts Receivable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			0.0
Fair Value, Nonrecurring | Level 1 | Inventory
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			0.0
Fair Value, Nonrecurring | Level 1 | Other Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			0.0
Fair Value, Nonrecurring | Level 2 | Prepublication assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	0.0
Fair Value, Nonrecurring | Level 2 | Operating lease right-of-use assets, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	0.0		0.0
Fair Value, Nonrecurring | Level 2 | Goodwill
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV		0.0
Fair Value, Nonrecurring | Level 2 | Intangible assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	0.0	0.0
Fair Value, Nonrecurring | Level 2 | Accounts Receivable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			0.0
Fair Value, Nonrecurring | Level 2 | Inventory
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			0.0
Fair Value, Nonrecurring | Level 2 | Other Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			0.0
Fair Value, Nonrecurring | Level 3 | Prepublication assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	3.0
Fair Value, Nonrecurring | Level 3 | Operating lease right-of-use assets, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	3.9		0.0
Fair Value, Nonrecurring | Level 3 | Goodwill
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV		7.6
Fair Value, Nonrecurring | Level 3 | Intangible assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV	$ 6.0	$ 4.1
Fair Value, Nonrecurring | Level 3 | Accounts Receivable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			1.4
Fair Value, Nonrecurring | Level 3 | Inventory
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			2.3
Fair Value, Nonrecurring | Level 3 | Other Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, FV			$ 0.0