Income Taxes	6 Months Ended
Income Taxes	Nov. 30, 2020
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. As of November 30, 2020 and May 31, 2020, recorded unrecognized tax benefits were $37.7 million and $35.9 million, respectively, and are included in long-term accrued liabilities on the consolidated condensed balance sheets. The majority of Cintas' operations are in North America. Cintas is required to file federal income tax returns, as well as state income tax returns in a majority of the domestic states and also in certain Canadian provinces. At times, Cintas is subject to audits in these jurisdictions. The audits, by nature, are sometimes complex and can require several years to resolve. The final resolution of any such tax audit could result in either a reduction in Cintas' accruals or an increase in its income tax provision, either of which could have an impact on the consolidated results of operations in any given period. All United States federal income tax returns are closed to audit through fiscal 2016. Cintas is currently in various audits in certain foreign jurisdictions and certain domestic states. The years under foreign and domestic state audits cover fiscal years back to 2013. Based on the resolution of the various audits and other potential regulatory developments, it is reasonably possible that the balance of unrecognized tax benefits would not change for the fiscal year ending May 31, 2021. Cintas’ effective tax rate was 13.3% and 20.1% for the three months ended November 30, 2020 and 2019, respectively. For the six months ended November 30, 2020 and 2019, Cintas' effective tax rate was 10.5% and 15.4%, respectively. The effective tax rate for all periods was impacted by certain discrete items (primarily the tax accounting for stock-based compensation). In addition, the effective tax rate for the three and six months ended November 30, 2020 included a one-time tax benefit on the sale of certain operating assets.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.