Goodwill - Schedule of Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Goodwill [Roll Forward]
Beginning balance	$ 2,752	$ 2,752
Ending balance	2,752	2,752
Consumer Bank
Goodwill [Roll Forward]
Beginning balance	1,819	1,819
Ending balance	1,819	1,819
Commercial Bank
Goodwill [Roll Forward]
Beginning balance	933	933
Ending balance	$ 933	$ 933