v3.26.1
Net Earnings (Loss) per Share - Schedule of Earnings (Loss) per Share (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Earnings Per Share [Abstract]        
Net earnings (loss) attributable to FIS $ 231 $ (470) $ 2,598 $ (393)
Weighted average shares outstanding-basic (in shares) 516 525 516 527
Plus: Common stock equivalent shares (in shares) 1 0 1 0
Weighted average shares outstanding-diluted (in shares) 517 525 517 527
Net earnings (loss) per share-basic attributable to FIS (in dollars per share) $ 0.45 $ (0.90) $ 5.03 $ (0.75)
Net earnings (loss) per share-diluted attributable to FIS (in dollars per share) $ 0.45 $ (0.90) $ 5.03 $ (0.75)