Fair Value Measurements - Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Assets
Mortgage loans held for sale	$ 2,603	$ 2,211
Liabilities
Mortgage servicing rights financing	32	32
Recurring Fair Value Measurements
Assets
Mortgage loans held for sale	2,603	2,211
Mortgage servicing rights	11,345	11,736
Equity investments	5	9
Liabilities
Mortgage servicing rights financing	32	32
Excess spread financing	366	386
Recurring Fair Value Measurements \| Forward MBS trades
Assets
Fair Value	8	6
Fair Value	2	7
Recurring Fair Value Measurements \| Treasury futures
Assets
Fair Value	1	59
Recurring Fair Value Measurements \| Forward Contracts [Member]
Assets
Fair Value	15	18
Fair Value	16	95
Recurring Fair Value Measurements \| Treasury futures, Assets [Member]
Assets
Fair Value	54
Recurring Fair Value Measurements \| Interest Rate Lock Commitments [Member]
Assets
Fair Value	38	22
Recurring Fair Value Measurements \| Level 1
Assets
Mortgage loans held for sale	0	0
Mortgage servicing rights	0	0
Equity investments	0	1
Liabilities
Mortgage servicing rights financing	0	0
Excess spread financing	0	0
Recurring Fair Value Measurements \| Level 1 \| Forward MBS trades
Assets
Fair Value	0	0
Fair Value	0	0
Recurring Fair Value Measurements \| Level 1 \| Treasury futures
Assets
Fair Value	0	0
Recurring Fair Value Measurements \| Level 1 \| Forward Contracts [Member]
Assets
Fair Value	0	0
Fair Value	0	0
Recurring Fair Value Measurements \| Level 1 \| Treasury futures, Assets [Member]
Assets
Fair Value	0
Recurring Fair Value Measurements \| Level 1 \| Interest Rate Lock Commitments [Member]
Assets
Fair Value	0	0
Recurring Fair Value Measurements \| Level 2
Assets
Mortgage loans held for sale	2,523	2,151
Mortgage servicing rights	0	0
Equity investments	0	0
Liabilities
Mortgage servicing rights financing	0	0
Excess spread financing	0	0
Recurring Fair Value Measurements \| Level 2 \| Forward MBS trades
Assets
Fair Value	0	0
Fair Value	0	0
Recurring Fair Value Measurements \| Level 2 \| Treasury futures
Assets
Fair Value	1	59
Recurring Fair Value Measurements \| Level 2 \| Forward Contracts [Member]
Assets
Fair Value	15	18
Fair Value	16	95
Recurring Fair Value Measurements \| Level 2 \| Treasury futures, Assets [Member]
Assets
Fair Value	54
Recurring Fair Value Measurements \| Level 2 \| Interest Rate Lock Commitments [Member]
Assets
Fair Value	0	0
Recurring Fair Value Measurements \| Level 3
Assets
Mortgage loans held for sale	80	60
Mortgage servicing rights	11,345	11,736
Equity investments	5	8
Liabilities
Mortgage servicing rights financing	32	32
Excess spread financing	366	386
Recurring Fair Value Measurements \| Level 3 \| Forward MBS trades
Assets
Fair Value	8	6
Fair Value	2	7
Recurring Fair Value Measurements \| Level 3 \| Treasury futures
Assets
Fair Value	0	0
Recurring Fair Value Measurements \| Level 3 \| Forward Contracts [Member]
Assets
Fair Value	0	0
Fair Value	0	0
Recurring Fair Value Measurements \| Level 3 \| Treasury futures, Assets [Member]
Assets
Fair Value	0
Recurring Fair Value Measurements \| Level 3 \| Interest Rate Lock Commitments [Member]
Assets
Fair Value	$ 38	$ 22

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Fair value of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, not subject to a master netting arrangement.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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