Mortgage Servicing Rights - Changes in Fair Value of Capitalized MSRs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Servicing Asset at Fair Value, Amount [Roll Forward]
Balance at beginning of period	$ 3,312	$ 3,462	$ 3,369	$ 3,377
Rights purchased	0	1	0	1
Rights capitalized	64	64	123	119
Rights sold	0	(189)	1	(189)
Changes in fair value of MSRs
Due to fluctuations in market interest rates	9	45	(40)	148
Due to revised assumptions or models	6	33	10	41
Other changes in fair value	(86)	(90)	(158)	(171)
Balance at end of period	$ 3,305	$ 3,326	$ 3,305	$ 3,326