Quarterly report pursuant to Section 13 or 15(d)

Service Revenue (Summary of Disaggregates Revenue by Services) (Details)

v3.19.1
Service Revenue (Summary of Disaggregates Revenue by Services) (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Feb. 28, 2019
Feb. 28, 2018
 [1]
Feb. 28, 2019
Feb. 28, 2018
 [1]
Disaggregation of Revenue [Line Items]        
Total service revenue $ 1,047.4 $ 918.0 $ 2,733.7 $ 2,486.2
Management Solutions [Member]        
Disaggregation of Revenue [Line Items]        
Total service revenue 801.6 768.8 2,174.7 2,088.2
PEO And Insurance Services [Member]        
Disaggregation of Revenue [Line Items]        
Total service revenue [2] $ 245.8 $ 149.2 $ 559.0 $ 398.0
[1] Amounts have been adjusted to reflect the adoption of Accounting Standards Codification ("ASC") Topic 606, "Revenue from Contracts with Customers" ("ASC Topic 606").
[2] Professional Employer Organization ("PEO") revenue is reported net of certain direct pass-through costs billed and incurred, which include payroll wages, payroll taxes, including federal and state unemployment insurance, and certain guaranteed benefit plan direct costs. Refer to Note B for further details.