Quarterly report [Sections 13 or 15(d)]

SEGMENT INFORMATION - Segment Information (Details)

v3.26.1
SEGMENT INFORMATION - Segment Information (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Segment Reporting Information [Line Items]      
Operating Revenue $ 1,648.9 $ 1,442.0  
Cost of services 767.1 656.7  
Selling, general and administrative expenses 411.0 374.9  
Depreciation and amortization expenses 183.1 174.6  
Operating income 287.7 235.8  
General corporate expense (1,361.2) (1,206.2)  
Other income, net 3.8 2.5  
Interest expense (55.7) (52.9)  
Consolidated income before income taxes 235.8 185.4  
Assets 11,942.0   $ 11,864.2
Total capital expenditures 116.7 101.2  
Operating Segments      
Segment Reporting Information [Line Items]      
Operating Revenue 1,648.9 1,442.0  
Cost of services 731.3 623.2  
Selling, general and administrative expenses 291.8 272.0  
Depreciation and amortization expenses 160.0 151.6  
Operating income 465.8 395.2  
General corporate expense      
Segment Reporting Information [Line Items]      
General corporate expense (178.1) (159.4)  
Assets 814.3   813.3
Total capital expenditures 41.6 24.1  
Other income, net and Interest expense      
Segment Reporting Information [Line Items]      
Other income, net 3.8 2.5  
Interest expense (55.7) (52.9)  
Workforce Solutions | Operating Segments      
Segment Reporting Information [Line Items]      
Operating Revenue 683.1 618.6  
Cost of services 249.0 233.0  
Selling, general and administrative expenses 77.3 76.9  
Depreciation and amortization expenses 47.4 44.6  
Operating income 309.4 264.1  
Assets 4,104.5   4,067.6
Total capital expenditures 25.9 20.3  
U.S. Information Solutions | Operating Segments      
Segment Reporting Information [Line Items]      
Operating Revenue 605.6 499.9  
Cost of services 318.4 232.7  
Selling, general and administrative expenses 104.0 98.2  
Depreciation and amortization expenses 60.9 63.3  
Operating income 122.3 105.7  
Assets 3,351.6   3,354.1
Total capital expenditures 24.3 26.4  
International | Operating Segments      
Segment Reporting Information [Line Items]      
Operating Revenue 360.2 323.5  
Cost of services 163.9 157.5  
Selling, general and administrative expenses 110.5 96.9  
Depreciation and amortization expenses 51.7 43.7  
Operating income 34.1 25.4  
Assets 3,671.6   $ 3,629.2
Total capital expenditures $ 24.9 $ 30.4