Quarterly report [Sections 13 or 15(d)]

Segment Reporting - Schedule of Total Revenue, Net Income and Significant Expenses Used by the Chief Operating Decision Maker (Details)

v3.26.1
Segment Reporting - Schedule of Total Revenue, Net Income and Significant Expenses Used by the Chief Operating Decision Maker (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Feb. 28, 2026
Feb. 28, 2025
Feb. 28, 2026
Feb. 28, 2025
Segment Reporting Information [Line Items]        
Total revenue $ 1,808.9 $ 1,509.0 $ 4,906.5 $ 4,144.4
Core business operations:        
Depreciation and amortization     329.4 123.8
Non-core business operations:        
Total expenses 1,016.9 817.2 3,000.7 2,367.8
Interest expense, excluding Paycor acquisition-related costs (68.1) (9.4) (204.8) (28.5)
Acquisition-related costs [1]   (13.2)   (13.2)
Other income, net 15.1 16.6 55.7 51.7
Income before income taxes 739.0 685.8 1,756.7 1,786.6
Income tax expense 178.7 166.5 417.2 426.5
Net income 560.3 519.3 1,339.5 1,360.1
Core [Member]        
Core business operations:        
Compensation-related expenses 530.9 455.7 1,586.4 1,361.4
PEO direct insurance costs 139.7 127.7 415.3 388.8
Depreciation and amortization 50.6 43.1 147.9 123.8
Other segment items [2] 224.5 174.0 618.0 477.1
Noncore [Member]        
Non-core business operations:        
Acquisition-related costs [1] $ 71.2 $ 16.7 $ 233.1 $ 16.7
[1] Acquisition-related costs included in total expenses include the amortization of intangibles acquired in the acquisition of Paycor, compensation costs related to the acquisition and integration of Paycor, including replacement awards, severance, and retention bonuses, and other acquisition-related costs, primarily reflecting third-party professional service fees. In addition, acquisition-related costs included in interest expense for fiscal 2025 include the amortization of financing fees related to debt instruments associated with the financing of the Paycor acquisition and the excluded components of the initial fair value of the interest rate swaption contracts. Refer to Note H Supplemental Information for additional information regarding the Company's financing arrangements related to the acquisition of Paycor.
[2] Other segment items include professional service expense, marketing and advertising expenses, and other overhead expenses.