v3.24.3
Segment Information - Revenue (Net of Reimbursable Expenses) of the Reported Segments (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2024
Sep. 30, 2023
Sep. 30, 2024
Sep. 30, 2023
Segment Reporting Information [Line Items]        
Revenues $ 2,289 $ 2,166 $ 6,895 $ 6,569
Income from operations (766) 159 (274) 586
HWC [Member]        
Segment Reporting Information [Line Items]        
Revenues 1,345 1,298 3,973 3,833
R&B [Member]        
Segment Reporting Information [Line Items]        
Revenues 943 858 2,906 2,668
Operating Segments [Member]        
Segment Reporting Information [Line Items]        
Revenues 2,268 2,137 6,821 6,443
Income from operations 499 439 1,516 1,295
Operating Segments [Member] | HWC [Member]        
Segment Reporting Information [Line Items]        
Revenues 1,328 1,282 3,924 3,784
Income from operations 329 305 941 836
Operating Segments [Member] | R&B [Member]        
Segment Reporting Information [Line Items]        
Revenues 940 855 2,897 2,659
Income from operations $ 170 $ 134 $ 575 $ 459