Earnings Per Share - Schedule of Buyback Activity by Program (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Aug. 31, 2025	Aug. 31, 2024
Equity, Class of Treasury Stock [Line Items]
Shares acquired for taxes due (in shares)	520	744
Shares acquired for taxes due, average price (in dollars per share)	$ 223.04	$ 189.67
Shares acquired for taxes due	$ 116,083	$ 141,185
Total repurchase of Cintas common stock	$ 266,097	$ 614,802
Share Buyback Programs
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	703	2,732
Average Price per Share (in dollars per share)	$ 213.40	$ 173.40
Purchase Price	$ 150,014	$ 473,617
July 26, 2022 Plan
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	703	2,732
Average Price per Share (in dollars per share)	$ 213.40	$ 173.40
Purchase Price	$ 150,014	$ 473,617
July 23, 2024 Plan
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	0	0
Average Price per Share (in dollars per share)	$ 0	$ 0
Purchase Price	$ 0	$ 0