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Revenue Recognition - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
May 31, 2020 | May 31, 2019 | May 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |
Deferred commissions current | $ 76.2 | $ 69.6 |
Deferred commissions noncurrent | 227.1 | 206.0 |
Amortization of deferred commissions | $ 77.8 | $ 71.1 |
Revenue | Product concentration risk |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |
Concentration risk (as a percent) | 100.00% | 100.00% | 100.00%
Uniform Rental and Facility Services, First Aid and Safety Services and Fire Protection Services | Revenue |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |
Concentration risk (as a percent) | 95.00% | 95.00% |
Uniform Direct Sales | Revenue |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |
Concentration risk (as a percent) | 5.00% | 5.00% |

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