Employee Benefit Plans - Narrative (Details) - USD ($)	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Accrued benefit liability	$ 17,800,000	$ 21,500,000
Unrecognized net actuarial loss	$ 2,900,000	$ 5,000,000
Expected return on plan assets	4.80%	4.25%
Expected contributions next twelve months	$ 0
Expected contributions in year one	4,200,000
Expected contributions in year two	4,400,000
Expected contributions in year three	4,500,000
Expected contributions in year four	4,700,000
Expected contributions in year five	4,800,000
Expected contributions thereafter	61,900,000
Fair value of plan assets	66,723,000	$ 78,244,000	$ 68,341,000
Projected benefit obligation	84,546,000	99,728,000	105,357,000
Employer contributions	87,000	3,613,000
Supplemental Executive Retirement Plan (SERP)
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 10,500,000	9,100,000	8,400,000
United States Plan
Defined Benefit Plan Disclosure [Line Items]
Required years of service for plan eligibility	1 year
Employer contributions	$ 85,000,000	75,600,000	74,300,000
Canada | DPSP and RRSP
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	3,400,000	3,100,000	$ 2,600,000
Pension Plan of Immaterial Acquisitions
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8,400,000	9,200,000
Projected benefit obligation	$ 7,500,000	$ 8,900,000