Significant Accounting Policies - Estimated Useful Lives (Details)	12 Months Ended
	May 31, 2019
Minimum | Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, useful lives	30 years
Minimum | Building improvements
Property, Plant and Equipment [Line Items]
Property and equipment, useful lives	5 years
Minimum | Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, useful lives	3 years
Minimum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, useful lives	2 years
Maximum | Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, useful lives	40 years
Maximum | Building improvements
Property, Plant and Equipment [Line Items]
Property and equipment, useful lives	20 years
Maximum | Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, useful lives	10 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, useful lives	15 years