Income Taxes	6 Months Ended
Nov. 30, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In the normal course of business, Cintas provides for uncertain tax positions and the related interest, and adjusts its unrecognized tax benefits and accrued interest accordingly. During the three months ended November 30, 2014, unrecognized tax benefits increased by approximately $0.5 million and accrued interest increased by approximately $0.1 million. During the six months ended November 30, 2014, unrecognized tax benefits increased by approximately $1.0 million and accrued interest increased by approximately $0.2 million. All U.S. federal income tax returns are closed to audit through fiscal 2010. Cintas is currently in advanced stages of various audits in certain foreign jurisdictions and certain domestic states. The years under audit cover fiscal years back to 2005. Based on the resolution of the various audits and changes in tax law, it is reasonably possible that the balance of unrecognized tax benefits would not change for the fiscal year ending May 31, 2015. On September 13, 2013, the U.S. Department of the Treasury and the Internal Revenue Service released final tangible property regulations under Sections 162(a) and 263(a) of the Internal Revenue Code of 1986 regarding amounts paid to improve tangible property and acquire or produce tangible property, as well as proposed regulations regarding the disposition of property. The effective date of the final regulations was extended and will be effective for Cintas' fiscal year ending May 31, 2015. Cintas is reviewing these regulations and does not believe there will be a material impact on the consolidated financial statements when such regulations become effective.

Income Taxes

6 Months Ended

Nov. 30, 2014

In the normal course of business, Cintas provides for uncertain tax positions and the related interest, and adjusts its unrecognized tax benefits and accrued interest accordingly. During the three months ended November 30, 2014, unrecognized tax benefits increased by approximately $0.5 million and accrued interest increased by approximately $0.1 million. During the six months ended November 30, 2014, unrecognized tax benefits increased by approximately $1.0 million and accrued interest increased by approximately $0.2 million.

All U.S. federal income tax returns are closed to audit through fiscal 2010. Cintas is currently in advanced stages of various audits in certain foreign jurisdictions and certain domestic states. The years under audit cover fiscal years back to 2005. Based on the resolution of the various audits and changes in tax law, it is reasonably possible that the balance of unrecognized tax benefits would not change for the fiscal year ending May 31, 2015.

On September 13, 2013, the U.S. Department of the Treasury and the Internal Revenue Service released final tangible property regulations under Sections 162(a) and 263(a) of the Internal Revenue Code of 1986 regarding amounts paid to improve tangible property and acquire or produce tangible property, as well as proposed regulations regarding the disposition of property. The effective date of the final regulations was extended and will be effective for Cintas' fiscal year ending May 31, 2015. Cintas is reviewing these regulations and does not believe there will be a material impact on the consolidated financial statements when such regulations become effective.