Employee Benefit Plans - Schedule for measurement of benefit plan assets at fair value (Details) - Pension Plans - USD ($) $ in Millions	May 31, 2024	May 31, 2023	May 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 21.4	$ 19.6
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.9	1.0
Pooled, Common and Collective Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9.3	8.2
Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.0
U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1.1
International
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		4.7
Annuities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.2	3.3
Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1.3
U.K.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21.4	19.6	$ 30.4
U.K. | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.9	8.1
U.K. | Level 1 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.9	1.0
U.K. | Level 1 | Pooled, Common and Collective Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 1 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
U.K. | Level 1 | U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1.1
U.K. | Level 1 | International
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		4.7
U.K. | Level 1 | Annuities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 1 | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1.3
U.K. | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17.3	8.2
U.K. | Level 2 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 2 | Pooled, Common and Collective Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9.3	8.2
U.K. | Level 2 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.0
U.K. | Level 2 | U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
U.K. | Level 2 | International
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
U.K. | Level 2 | Annuities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 2 | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
U.K. | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.2	3.3
U.K. | Level 3 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 3 | Pooled, Common and Collective Funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 3 | Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
U.K. | Level 3 | U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
U.K. | Level 3 | International
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
U.K. | Level 3 | Annuities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 3.2	3.3
U.K. | Level 3 | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 0.0