Stock-Based Compensation - Schedule of Assumptions Used to Determine Fair Value of Options (Details) - Stock Options	12 Months Ended
	May 31, 2024	May 31, 2023	May 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	3.90%	2.80%	0.80%
Dividend yield	1.10%	1.10%	1.20%
Expected volatility of Cintas' common stock	26.90%	26.00%	25.20%
Expected life of the option in years	5 years 6 months	5 years 6 months	5 years 6 months