Employee Benefit Plans - Reconciliation of Level 3 Pension Assets (Details) - Defined Benefit Pension Plans - USD ($) $ in Millions	12 Months Ended
May 31, 2023	May 31, 2022
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	$ 126.2	$ 158.4
Fair value of plan assets at end of year	112.6	126.2
Total.
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	16.1	31.7
Sales	(4.8)	(15.3)
Return on plan assets related to assets still held at May 31	(0.9)	(0.3)
Fair value of plan assets at end of year	10.4	16.1
Significant other unobservable inputs (Level 3) \| Insurance Annuities
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	11.3	15.6
Sales		(4.3)
Return on plan assets related to assets still held at May 31	(0.9)
Fair value of plan assets at end of year	10.4	11.3
Measured at net asset value \| Hedge Funds
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year	4.8	5.1
Sales	$ (4.8)
Return on plan assets related to assets still held at May 31		(0.3)
Fair value of plan assets at end of year		4.8
Measured at net asset value \| Fund-of-funds
Change in the fair value of plan assets:
Fair value of plan assets at beginning of year		11.0
Sales		$ (11.0)

Amount, measured using unobservable inputs, of increase (decrease) in plan assets of defined benefit plan from sales.

No definition available.

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- Definition

Amount, measured using unobservable inputs, of increase (decrease) in plan assets of defined benefit plan from actual return (loss) on assets still held.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

+ References

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