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Debt, Derivatives and Hedging Activities - Summary of Debt Outstanding (Details) - USD ($)	Aug. 31, 2018	May 31, 2018	May 31, 2017
Debt due after one year
Debt issuance costs	$ (18,376,000)	$ (19,119,000)
Total debt due after one year	2,535,859,000	2,535,309,000
Senior notes \| Senior Notes 4.30%, 2022 Maturity
Debt due after one year
Long-term Debt, non-current	$ 250,000,000	250,000,000
Stated interest rate (as a percent)	4.30%
Senior notes \| Senior Notes, 2.90%, 2022 Maturity
Debt due after one year
Long-term Debt, non-current	$ 650,000,000	650,000,000
Stated interest rate (as a percent)	2.90%
Senior notes \| Senior Notes, 3.25%, 2023 Maturity
Debt due after one year
Long-term Debt, non-current	$ 300,000,000	300,000,000
Stated interest rate (as a percent)	3.25%
Senior notes \| Senior Notes, 2.78%, 2023 Maturity
Debt due after one year
Long-term Debt, non-current	$ 52,011,000	52,119,000
Stated interest rate (as a percent)	2.78%
Senior notes \| Senior Notes, 2.78%, 2023 Maturity \| G&K Services
Debt due after one year
Face value			$ 50,000,000.0
Stated interest rate (as a percent)			3.73%
Senior notes \| Senior Notes, 3.11%, 2025 Maturity
Debt due after one year
Long-term Debt, non-current	$ 52,224,000	52,309,000
Stated interest rate (as a percent)	3.11%
Senior notes \| Senior Notes, 3.11%, 2025 Maturity \| G&K Services
Debt due after one year
Face value			$ 50,000,000.0
Stated interest rate (as a percent)			3.88%
Senior notes \| Senior Notes, 3.70%, 2027 Maturity
Debt due after one year
Long-term Debt, non-current	$ 1,000,000,000	1,000,000,000
Stated interest rate (as a percent)	3.70%
Senior notes \| Senior Notes, 6.15%, 2037 Maturity
Debt due after one year
Long-term Debt, non-current	$ 250,000,000	$ 250,000,000
Stated interest rate (as a percent)	6.15%