v3.26.1
Revenue (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Disaggregation of Revenue [Line Items]          
Revenue $ 6,562.5 $ 4,015.6 $ 12,805.4 $ 7,706.0  
Revenue, entities classified as held for sale 567.5   1,200.0    
Media and production costs 1,905.9 889.6 1,905.9 889.6 $ 2,200.1
Unbilled fees and costs and contract assets 1,753.7 1,106.3 1,753.7 1,106.3 1,208.8
Work in process 3,659.6 1,995.9 3,659.6 1,995.9 3,408.9
Customer advances 2,134.4 1,348.2 2,134.4 1,348.2 $ 1,727.6
Remaining performance obligation, contracts greater than one year 455.7   455.7    
North America          
Disaggregation of Revenue [Line Items]          
Revenue 3,990.8 2,209.7 7,875.9 4,321.2  
United States          
Disaggregation of Revenue [Line Items]          
Revenue 3,800.0 2,100.0 7,500.0 4,100.0  
Latin America          
Disaggregation of Revenue [Line Items]          
Revenue 248.5 114.6 444.6 211.0  
Europe          
Disaggregation of Revenue [Line Items]          
Revenue 1,587.6 1,166.4 3,026.6 2,161.4  
Middle East and Africa          
Disaggregation of Revenue [Line Items]          
Revenue 141.7 66.1 285.9 136.9  
Asia-Pacific          
Disaggregation of Revenue [Line Items]          
Revenue 593.9 458.8 1,172.4 875.5  
Integrated Media          
Disaggregation of Revenue [Line Items]          
Revenue 3,259.4 1,999.1 6,237.8 3,804.4  
Advertising          
Disaggregation of Revenue [Line Items]          
Revenue 1,079.1 711.9 2,139.3 1,386.5  
Public Relations          
Disaggregation of Revenue [Line Items]          
Revenue 708.9 370.0 1,171.7 624.9  
Health          
Disaggregation of Revenue [Line Items]          
Revenue 586.0 325.9 1,405.5 729.1  
Experiential & Other          
Disaggregation of Revenue [Line Items]          
Revenue $ 929.1 $ 608.7 $ 1,851.1 $ 1,161.1