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)

v3.25.2
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
Aug. 31, 2025
Aug. 31, 2024
Segment Reporting Information [Line Items]    
Total revenue $ 1,540.0 $ 1,318.5
Core business operations:    
Depreciation and amortization 109.3 39.0
Non-core business operations:    
Total expenses 998.1 771.8
Interest expense (68.2) (9.6)
Other income, net 23.8 20.0
Income before income taxes 497.5 557.1
Income tax expense 113.7 129.7
Net income 383.8 427.4
Core [Member]    
Core business operations:    
Compensation-related expenses 530.0 451.3
PEO direct insurance costs 138.6 130.3
Depreciation and amortization 48.2 39.0
Other segment items [1] 196.5 $ 151.2
Noncore [Member]    
Non-core business operations:    
Acquisition-related costs [2] $ 84.8  
[1] Other segment items include professional service expense, marketing and advertising expenses, and other overhead expenses.
[2] 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.