v3.26.1
Revenue Recognition - Disaggregation of Revenue (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disaggregation of Revenue [Line Items]    
Revenue $ 4,510.4 $ 4,090.3
Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 4,510.4 4,090.3
Intercompany Eliminations    
Disaggregation of Revenue [Line Items]    
Revenue (7.1) (7.6)
Americas | Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 1,115.6 1,056.7
Americas | Services transferred over time    
Disaggregation of Revenue [Line Items]    
Revenue 1,095.5 1,037.4
Americas | Services transferred at a point in time    
Disaggregation of Revenue [Line Items]    
Revenue 20.1 19.3
Americas | United States    
Disaggregation of Revenue [Line Items]    
Revenue   688.8
Americas | United States | Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 654.9 [1] 688.8 [2]
Americas | United States | Services transferred over time    
Disaggregation of Revenue [Line Items]    
Revenue 640.9 673.6
Americas | United States | Services transferred at a point in time    
Disaggregation of Revenue [Line Items]    
Revenue 14.0 15.2
Americas | Other Americas    
Disaggregation of Revenue [Line Items]    
Revenue   367.9
Americas | Other Americas | Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 460.7 367.9
Americas | Other Americas | Services transferred over time    
Disaggregation of Revenue [Line Items]    
Revenue 454.6 363.8
Americas | Other Americas | Services transferred at a point in time    
Disaggregation of Revenue [Line Items]    
Revenue 6.1 4.1
Americas | Staffing and Interim    
Disaggregation of Revenue [Line Items]    
Revenue 1,014.0 958.3
Americas | Staffing and Interim | United States    
Disaggregation of Revenue [Line Items]    
Revenue 582.9 616.1
Americas | Staffing and Interim | Other Americas    
Disaggregation of Revenue [Line Items]    
Revenue 431.1 342.2
Americas | Outcome-Based Solutions and Consulting    
Disaggregation of Revenue [Line Items]    
Revenue 18.9 17.1
Americas | Outcome-Based Solutions and Consulting | United States    
Disaggregation of Revenue [Line Items]    
Revenue 2.1 2.3
Americas | Outcome-Based Solutions and Consulting | Other Americas    
Disaggregation of Revenue [Line Items]    
Revenue 16.8 14.8
Americas | Permanent Recruitment    
Disaggregation of Revenue [Line Items]    
Revenue 36.8 37.6
Americas | Permanent Recruitment | United States    
Disaggregation of Revenue [Line Items]    
Revenue 27.5 29.3
Americas | Permanent Recruitment | Other Americas    
Disaggregation of Revenue [Line Items]    
Revenue 9.3 8.3
Americas | Other    
Disaggregation of Revenue [Line Items]    
Revenue 45.9 43.7
Americas | Other | United States    
Disaggregation of Revenue [Line Items]    
Revenue 42.4 41.1
Americas | Other | Other Americas    
Disaggregation of Revenue [Line Items]    
Revenue 3.5 2.6
Southern Europe | Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 2,101.3 1,834.0
Southern Europe | Services transferred over time    
Disaggregation of Revenue [Line Items]    
Revenue 2,065.7 1,801.4
Southern Europe | Services transferred at a point in time    
Disaggregation of Revenue [Line Items]    
Revenue 35.6 32.6
Southern Europe | France    
Disaggregation of Revenue [Line Items]    
Revenue   965.7
Southern Europe | France | Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 1,068.6 965.7
Southern Europe | France | Services transferred over time    
Disaggregation of Revenue [Line Items]    
Revenue 1,058.4 955.1
Southern Europe | France | Services transferred at a point in time    
Disaggregation of Revenue [Line Items]    
Revenue 10.2 10.6
Southern Europe | Italy    
Disaggregation of Revenue [Line Items]    
Revenue   397.8
Southern Europe | Italy | Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 474.7 397.8
Southern Europe | Italy | Services transferred over time    
Disaggregation of Revenue [Line Items]    
Revenue 461.8 386.6
Southern Europe | Italy | Services transferred at a point in time    
Disaggregation of Revenue [Line Items]    
Revenue 12.9 11.2
Southern Europe | Other Southern Europe    
Disaggregation of Revenue [Line Items]    
Revenue   470.5
Southern Europe | Other Southern Europe | Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 558.0 470.5
Southern Europe | Other Southern Europe | Services transferred over time    
Disaggregation of Revenue [Line Items]    
Revenue 545.5 459.7
Southern Europe | Other Southern Europe | Services transferred at a point in time    
Disaggregation of Revenue [Line Items]    
Revenue 12.5 10.8
Southern Europe | Staffing and Interim    
Disaggregation of Revenue [Line Items]    
Revenue 1,860.2 1,611.8
Southern Europe | Staffing and Interim | France    
Disaggregation of Revenue [Line Items]    
Revenue 972.0 871.6
Southern Europe | Staffing and Interim | Italy    
Disaggregation of Revenue [Line Items]    
Revenue 441.8 368.8
Southern Europe | Staffing and Interim | Other Southern Europe    
Disaggregation of Revenue [Line Items]    
Revenue 446.4 371.4
Southern Europe | Outcome-Based Solutions and Consulting    
Disaggregation of Revenue [Line Items]    
Revenue 166.7 151.2
Southern Europe | Outcome-Based Solutions and Consulting | France    
Disaggregation of Revenue [Line Items]    
Revenue 65.5 64.0
Southern Europe | Outcome-Based Solutions and Consulting | Italy    
Disaggregation of Revenue [Line Items]    
Revenue 13.8 11.1
Southern Europe | Outcome-Based Solutions and Consulting | Other Southern Europe    
Disaggregation of Revenue [Line Items]    
Revenue 87.4 76.1
Southern Europe | Permanent Recruitment    
Disaggregation of Revenue [Line Items]    
Revenue 40.8 37.0
Southern Europe | Permanent Recruitment | France    
Disaggregation of Revenue [Line Items]    
Revenue 10.9 11.3
Southern Europe | Permanent Recruitment | Italy    
Disaggregation of Revenue [Line Items]    
Revenue 13.7 12.0
Southern Europe | Permanent Recruitment | Other Southern Europe    
Disaggregation of Revenue [Line Items]    
Revenue 16.2 13.7
Southern Europe | Other    
Disaggregation of Revenue [Line Items]    
Revenue 33.6  
Southern Europe | Other | France    
Disaggregation of Revenue [Line Items]    
Revenue 20.2 18.8
Southern Europe | Other | Italy    
Disaggregation of Revenue [Line Items]    
Revenue 5.4 5.9
Southern Europe | Other | Other Southern Europe    
Disaggregation of Revenue [Line Items]    
Revenue 8.0 9.3
Northern Europe | Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 790.1 730.8
Northern Europe | Services transferred over time    
Disaggregation of Revenue [Line Items]    
Revenue 773.8 710.3
Northern Europe | Services transferred at a point in time    
Disaggregation of Revenue [Line Items]    
Revenue 16.3 20.5
Northern Europe | Staffing and Interim    
Disaggregation of Revenue [Line Items]    
Revenue 680.6 621.0
Northern Europe | Outcome-Based Solutions and Consulting    
Disaggregation of Revenue [Line Items]    
Revenue 60.3 58.7
Northern Europe | Permanent Recruitment    
Disaggregation of Revenue [Line Items]    
Revenue 23.9 26.7
Northern Europe | Other    
Disaggregation of Revenue [Line Items]    
Revenue 25.3 24.4
APME | Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 510.5 476.4
APME | Services transferred over time    
Disaggregation of Revenue [Line Items]    
Revenue 500.8 466.8
APME | Services transferred at a point in time    
Disaggregation of Revenue [Line Items]    
Revenue 9.7 9.6
APME | Staffing and Interim    
Disaggregation of Revenue [Line Items]    
Revenue 430.6 396.0
APME | Outcome-Based Solutions and Consulting    
Disaggregation of Revenue [Line Items]    
Revenue 58.7 60.5
APME | Permanent Recruitment    
Disaggregation of Revenue [Line Items]    
Revenue 11.4 11.3
APME | Other    
Disaggregation of Revenue [Line Items]    
Revenue 9.8 8.6
Northern Europe and APME | Reportable subsegments    
Disaggregation of Revenue [Line Items]    
Revenue 4,517.5 4,097.9
Northern Europe and APME | Services transferred over time    
Disaggregation of Revenue [Line Items]    
Revenue 4,435.8 4,015.9
Northern Europe and APME | Services transferred at a point in time    
Disaggregation of Revenue [Line Items]    
Revenue 81.7 82.0
Northern Europe and APME | Staffing and Interim    
Disaggregation of Revenue [Line Items]    
Revenue 3,985.4 3,587.1
Northern Europe and APME | Outcome-Based Solutions and Consulting    
Disaggregation of Revenue [Line Items]    
Revenue 304.6 287.5
Northern Europe and APME | Permanent Recruitment    
Disaggregation of Revenue [Line Items]    
Revenue 112.9 112.6
Northern Europe and APME | Other    
Disaggregation of Revenue [Line Items]    
Revenue $ 114.6 $ 110.7
[1] The United States revenues above represent revenues from our company-owned branches and franchise fees received from our franchise operations, which were $2.4 for the three months ended March 31, 2026.
[2] The United States revenues above represent revenues from our company-owned branches and franchise fees received from our franchise operations, which were $2.2 for the three months ended March 31, 2025.