Mortgage Servicing Rights - Changes in Fair Value of Capitalized MSRs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Servicing Asset at Fair Value, Amount [Roll Forward]
Balance at beginning of period	$ 3,462	$ 3,724	$ 3,377	$ 3,755
Rights purchased	1	1	1	2
Rights capitalized	64	99	119	195
Rights sold	(189)	(149)	(189)	(148)
Changes in fair value of MSRs
Due to fluctuations in market interest rates	45	84	148	46
Due to revised assumptions or models	33	(21)	41	(16)
Other changes in fair value	(90)	(105)	(171)	(201)
Balance at end of period	$ 3,326	$ 3,633	$ 3,326	$ 3,633