Goodwill and Mortgage Servicing Rights - Goodwill Changes During Period (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Goodwill [Roll Forward]
Balance at beginning of period	$ 52,711	$ 52,747	$ 52,731	$ 52,565
Changes during the period from:
Other	6	(30)	(14)	152
Balance at end of period	$ 52,717	$ 52,717	$ 52,717	$ 52,717

Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

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+ Details