v3.26.1
Revenues and Trade Accounts Receivable - Disaggregation of Revenue (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation of Revenue [Line Items]        
Revenue $ 5,481 $ 5,245 $ 10,894 $ 10,360
Time-and-materials        
Disaggregation of Revenue [Line Items]        
Revenue 2,305 2,341 4,516 4,576
Fixed-price        
Disaggregation of Revenue [Line Items]        
Revenue 2,690 2,413 5,414 4,823
Transaction or volume-based        
Disaggregation of Revenue [Line Items]        
Revenue 486 491 964 961
North America        
Disaggregation of Revenue [Line Items]        
Revenue 4,127 3,912 8,179 7,766
United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 492 482 1,001 939
Europe, excluding United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 535 520 1,065 1,013
Europe        
Disaggregation of Revenue [Line Items]        
Revenue 1,027 1,002 2,066 1,952
Rest of World        
Disaggregation of Revenue [Line Items]        
Revenue 327 331 649 642
Consulting And Technology Services        
Disaggregation of Revenue [Line Items]        
Revenue 3,518 3,389 7,009 6,615
Outsourcing Services        
Disaggregation of Revenue [Line Items]        
Revenue 1,963 1,856 3,885 3,745
Healthcare Segment        
Disaggregation of Revenue [Line Items]        
Revenue 1,572 1,551 3,151 3,122
Healthcare Segment | Time-and-materials        
Disaggregation of Revenue [Line Items]        
Revenue 487 495 961 976
Healthcare Segment | Fixed-price        
Disaggregation of Revenue [Line Items]        
Revenue 803 750 1,609 1,541
Healthcare Segment | Transaction or volume-based        
Disaggregation of Revenue [Line Items]        
Revenue 282 306 581 605
Healthcare Segment | North America        
Disaggregation of Revenue [Line Items]        
Revenue 1,307 1,298 2,618 2,628
Healthcare Segment | United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 60 51 117 100
Healthcare Segment | Europe, excluding United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 164 166 332 326
Healthcare Segment | Europe        
Disaggregation of Revenue [Line Items]        
Revenue 224 217 449 426
Healthcare Segment | Rest of World        
Disaggregation of Revenue [Line Items]        
Revenue 41 36 84 68
Healthcare Segment | Consulting And Technology Services        
Disaggregation of Revenue [Line Items]        
Revenue 925 908 1,838 1,778
Healthcare Segment | Outsourcing Services        
Disaggregation of Revenue [Line Items]        
Revenue 647 643 1,313 1,344
Financial Services        
Disaggregation of Revenue [Line Items]        
Revenue 1,733 1,547 3,377 3,009
Financial Services | Time-and-materials        
Disaggregation of Revenue [Line Items]        
Revenue 848 812 1,628 1,576
Financial Services | Fixed-price        
Disaggregation of Revenue [Line Items]        
Revenue 825 687 1,633 1,338
Financial Services | Transaction or volume-based        
Disaggregation of Revenue [Line Items]        
Revenue 60 48 116 95
Financial Services | North America        
Disaggregation of Revenue [Line Items]        
Revenue 1,263 1,096 2,439 2,139
Financial Services | United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 165 159 336 312
Financial Services | Europe, excluding United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 167 160 333 307
Financial Services | Europe        
Disaggregation of Revenue [Line Items]        
Revenue 332 319 669 619
Financial Services | Rest of World        
Disaggregation of Revenue [Line Items]        
Revenue 138 132 269 251
Financial Services | Consulting And Technology Services        
Disaggregation of Revenue [Line Items]        
Revenue 1,255 1,099 2,440 2,119
Financial Services | Outsourcing Services        
Disaggregation of Revenue [Line Items]        
Revenue 478 448 937 890
Products and Resources        
Disaggregation of Revenue [Line Items]        
Revenue 1,322 1,306 2,643 2,584
Products and Resources | Time-and-materials        
Disaggregation of Revenue [Line Items]        
Revenue 515 580 1,038 1,136
Products and Resources | Fixed-price        
Disaggregation of Revenue [Line Items]        
Revenue 718 638 1,431 1,272
Products and Resources | Transaction or volume-based        
Disaggregation of Revenue [Line Items]        
Revenue 89 88 174 176
Products and Resources | North America        
Disaggregation of Revenue [Line Items]        
Revenue 918 918 1,834 1,829
Products and Resources | United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 151 148 315 285
Products and Resources | Europe, excluding United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 171 159 332 312
Products and Resources | Europe        
Disaggregation of Revenue [Line Items]        
Revenue 322 307 647 597
Products and Resources | Rest of World        
Disaggregation of Revenue [Line Items]        
Revenue 82 81 162 158
Products and Resources | Consulting And Technology Services        
Disaggregation of Revenue [Line Items]        
Revenue 900 918 1,801 1,805
Products and Resources | Outsourcing Services        
Disaggregation of Revenue [Line Items]        
Revenue 422 388 842 779
Communications, Media and Technology        
Disaggregation of Revenue [Line Items]        
Revenue 854 841 1,723 1,645
Communications, Media and Technology | Time-and-materials        
Disaggregation of Revenue [Line Items]        
Revenue 455 454 889 888
Communications, Media and Technology | Fixed-price        
Disaggregation of Revenue [Line Items]        
Revenue 344 338 741 672
Communications, Media and Technology | Transaction or volume-based        
Disaggregation of Revenue [Line Items]        
Revenue 55 49 93 85
Communications, Media and Technology | North America        
Disaggregation of Revenue [Line Items]        
Revenue 639 600 1,288 1,170
Communications, Media and Technology | United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 116 124 233 242
Communications, Media and Technology | Europe, excluding United Kingdom        
Disaggregation of Revenue [Line Items]        
Revenue 33 35 68 68
Communications, Media and Technology | Europe        
Disaggregation of Revenue [Line Items]        
Revenue 149 159 301 310
Communications, Media and Technology | Rest of World        
Disaggregation of Revenue [Line Items]        
Revenue 66 82 134 165
Communications, Media and Technology | Consulting And Technology Services        
Disaggregation of Revenue [Line Items]        
Revenue 438 464 930 913
Communications, Media and Technology | Outsourcing Services        
Disaggregation of Revenue [Line Items]        
Revenue $ 416 $ 377 $ 793 $ 732