Fair Value Measurements - Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Assets
Mortgage loans held for sale	$ 2,475	$ 2,211
Liabilities
Mortgage servicing rights financing	24	32
Recurring Fair Value Measurements
Assets
Mortgage loans held for sale	2,475	2,211
Mortgage servicing rights	11,431	11,736
Equity investments	5	9
Liabilities
Mortgage servicing rights financing	24	32
Excess spread financing	357	386
Recurring Fair Value Measurements \| Treasury futures
Assets
Fair Value		59
Recurring Fair Value Measurements \| Forward Contracts [Member]
Assets
Fair Value	118	18
Fair Value	34	95
Recurring Fair Value Measurements \| Treasury futures, Assets [Member]
Assets
Fair Value	79
Recurring Fair Value Measurements \| Interest Rate Lock Commitments [Member]
Assets
Fair Value	41	22
Recurring Fair Value Measurements \| Loan Purchase Commitments [Member]
Assets
Fair Value	12	6
Fair Value	1	7
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 \| Treasury futures
Assets
Fair Value		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 1 \| Loan Purchase Commitments [Member]
Assets
Fair Value	0	0
Fair Value	0	0
Recurring Fair Value Measurements \| Level 2
Assets
Mortgage loans held for sale	2,411	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 \| Treasury futures
Assets
Fair Value		59
Recurring Fair Value Measurements \| Level 2 \| Forward Contracts [Member]
Assets
Fair Value	118	18
Fair Value	34	95
Recurring Fair Value Measurements \| Level 2 \| Treasury futures, Assets [Member]
Assets
Fair Value	79
Recurring Fair Value Measurements \| Level 2 \| Interest Rate Lock Commitments [Member]
Assets
Fair Value	0	0
Recurring Fair Value Measurements \| Level 2 \| Loan Purchase Commitments [Member]
Assets
Fair Value	0	0
Fair Value	0	0
Recurring Fair Value Measurements \| Level 3
Assets
Mortgage loans held for sale	64	60
Mortgage servicing rights	11,431	11,736
Equity investments	5	8
Liabilities
Mortgage servicing rights financing	24	32
Excess spread financing	357	386
Recurring Fair Value Measurements \| Level 3 \| Treasury futures
Assets
Fair Value		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	41	22
Recurring Fair Value Measurements \| Level 3 \| Loan Purchase Commitments [Member]
Assets
Fair Value	12	6
Fair Value	$ 1	$ 7

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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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Fair value portion of mortgage loans held-for-sale.

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Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

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