Stock-Based Compensation - Schedule of Assumptions Used to Determine Fair Value of Options (Details) - Stock Options	12 Months Ended
	May 31, 2025	May 31, 2024	May 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	4.30%	3.90%	2.80%
Dividend yield	1.10%	1.10%	1.10%
Expected volatility of Cintas' common stock	26.50%	26.90%	26.00%
Expected life of the option in years	5 years 6 months	5 years 6 months	5 years 6 months