Employee Benefit Plans - Schedule for measurement of benefit plan assets at fair value (Details) - Pension Plans - USD ($) $ in Millions	May 31, 2022	May 31, 2021	May 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 30.4	$ 40.8
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.3	0.9
U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.4	4.7
International
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14.7	14.5
Annuities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.1	13.0
Annuities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.2	6.0
Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.7	1.7
U.K.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	30.4	40.8	$ 36.6
U.K. | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	19.1	21.8
U.K. | Level 1 | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.3	0.9
U.K. | Level 1 | U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.4	4.7
U.K. | Level 1 | International
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14.7	14.5
U.K. | Level 1 | Annuities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
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	1.7	1.7
U.K. | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.1	13.0
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 | U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 2 | International
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 2 | Annuities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.1	13.0
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	0.0
U.K. | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.2	6.0
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 | U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 3 | International
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 3 | Annuities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
U.K. | Level 3 | Annuities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.2	6.0
U.K. | Level 3 | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0.0	$ 0.0