Fair Value Measurements - Assets Measured by using Significant Unobservable Inputs (Details) - Significant Unobservable Inputs (Level 3) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at Beginning of Year	$ 1,033
Total Gains / (Losses) Recorded in Earnings	$ (10)	[1]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Return On Mortgage Servicing Rights
Purchases / Originations	$ 24
Transfers In (Out)	(15)
Balance at End of Year	1,032
Mortgage Servicing Rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at Beginning of Year	1,012	[1]
Total Gains / (Losses) Recorded in Earnings	$ 2	[1]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Return On Mortgage Servicing Rights
Purchases / Originations	$ 19	[1]
Balance at End of Year	1,033	[1]
Rate Lock Commitments Net
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at Beginning of Year	21	[2]
Total Gains / (Losses) Recorded in Earnings	$ (12)	[1],[2]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Return On Mortgage Servicing Rights
Purchases / Originations	$ 5	[2]
Transfers In (Out)	(15)	[2]
Balance at End of Year	$ (1)	[1],[2]

[1] We utilized swaptions, futures, forward agency and loan sales and interest rate swaps to manage the risk associated with mortgage servicing rights and rate lock commitments. Gains and losses for individual lines do not reflect the effect of our risk management activities related to such Level 3 instruments.

[2] Rate lock commitments are reported on a fallout-adjusted basis. Transfers out of Level 3 represent the settlement value of the commitments that are transferred to LHFS, which are classified as Level 2 assets.