Annual report pursuant to Section 13 and 15(d)

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

v3.19.2
Service Revenue (Summary of Disaggregates Revenue by Services) (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
May 31, 2019
Feb. 28, 2019
Nov. 30, 2018
Aug. 31, 2018
May 31, 2018
 [1]
Feb. 28, 2018
 [1]
Nov. 30, 2017
 [1]
Aug. 31, 2017
 [1]
May 31, 2019
May 31, 2018
 [2]
May 31, 2017
 [2],[3]
Disaggregation of Revenue [Line Items]                      
Total service revenue $ 958.2 $ 1,047.4 $ 840.6 $ 845.7 $ 828.0 $ 918.0 $ 789.0 $ 779.2 $ 3,691.9 $ 3,314.2 [1] $ 3,102.4
Management Solutions [Member]                      
Disaggregation of Revenue [Line Items]                      
Total service revenue                 2,877.7 2,758.4 [3] 2,680.7
PEO And Insurance Services [Member]                      
Disaggregation of Revenue [Line Items]                      
Total service revenue                 $ 814.2 $ 555.8 [3] $ 421.7
[1] Amounts have been adjusted to reflect the adoption of ASC Topic 606.
[2] Amounts have been adjusted to reflect the adoption of Accounting Standards Codification ("ASC") Topic 606, "Revenue from Contracts with Customers" ("ASC Topic 606").
[3] Amounts have been adjusted to reflect the adoption of ASC Topic 606.