Earnings per Share - Summary of Buyback Activity by Program (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended			22 Months Ended
	May 31, 2023	May 31, 2022	May 31, 2021	May 31, 2023
Equity, Class of Treasury Stock [Line Items]
Purchase Price	$ 398,865	$ 1,525,873	$ 554,121
Shares acquired for taxes due (in shares)	430	305	246
Shares acquired for taxes due, average price (in dollars per share)	$ 420.21	$ 397.16	$ 302.52
Shares acquired for taxes due	$ 180,577	$ 121,224	$ 74,465
Total repurchase of Cintas common stock	$ 398,865	$ 1,525,873	$ 554,121
Share Repurchase Programs
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	550	3,740	1,386
Average Price per Share (in dollars per share)	$ 396.69	$ 375.53	$ 346.13
Purchase Price	$ 218,288	$ 1,404,649	$ 479,656
Share Buyback Program October 2018
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	0	0	190
Average Price per Share (in dollars per share)	$ 0	$ 0	$ 319.88
Purchase Price	$ 0	$ 0	$ 60,877
Share Buyback Program October 2019
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	0	1,590	1,196
Average Price per Share (in dollars per share)	$ 0	$ 365.41	$ 350.31
Purchase Price	$ 0	$ 581,220	$ 418,779
Share Buyback Program July 27 2021
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	550	2,150	0	2,700
Average Price per Share (in dollars per share)	$ 396.69	$ 383.01	$ 0	$ 385.80
Purchase Price	$ 218,288	$ 823,429	$ 0	$ 1,000,000
Share Buyback Program July 26 2022
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	0	0	0
Average Price per Share (in dollars per share)	$ 0	$ 0	$ 0
Purchase Price	$ 0	$ 0	$ 0