Fair Value Measurements - Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Assets
Mortgage loans held for sale	$ 1,581	$ 4,381
Liabilities
Mortgage servicing rights financing	20	10
Treasury futures
Assets
Fair Value	62
Recurring Fair Value Measurements
Assets
Mortgage loans held for sale	1,581	4,381
Mortgage servicing rights	6,408	4,223
Equity investments	48	63
Liabilities
Mortgage servicing rights financing	20	10
Excess spread financing	519	768
Recurring Fair Value Measurements \| IRLCs
Assets
Fair Value	21	134
Fair Value	8
Recurring Fair Value Measurements \| LPCs
Assets
Fair Value	1	3
Fair Value	5	2
Recurring Fair Value Measurements \| Forward MBS trades
Assets
Fair Value	74	7
Fair Value	19	8
Recurring Fair Value Measurements \| Swap futures
Assets
Fair Value		6
Recurring Fair Value Measurements \| Level 1
Assets
Mortgage loans held for sale	0	0
Mortgage servicing rights	0	0
Equity investments	3	9
Liabilities
Mortgage servicing rights financing	0	0
Excess spread financing	0	0
Recurring Fair Value Measurements \| Level 1 \| IRLCs
Assets
Fair Value	0	0
Fair Value	0
Recurring Fair Value Measurements \| Level 1 \| LPCs
Assets
Fair Value	0	0
Fair Value	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 \| Swap futures
Assets
Fair Value		0
Recurring Fair Value Measurements \| Level 1 \| Treasury futures
Assets
Fair Value	0
Recurring Fair Value Measurements \| Level 2
Assets
Mortgage loans held for sale	1,581	4,381
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 \| IRLCs
Assets
Fair Value	0	0
Fair Value	0
Recurring Fair Value Measurements \| Level 2 \| LPCs
Assets
Fair Value	0	0
Fair Value	0	0
Recurring Fair Value Measurements \| Level 2 \| Forward MBS trades
Assets
Fair Value	74	7
Fair Value	19	8
Recurring Fair Value Measurements \| Level 2 \| Swap futures
Assets
Fair Value		6
Recurring Fair Value Measurements \| Level 2 \| Treasury futures
Assets
Fair Value	62
Recurring Fair Value Measurements \| Level 3
Assets
Mortgage loans held for sale	0	0
Mortgage servicing rights	6,408	4,223
Equity investments	45	54
Liabilities
Mortgage servicing rights financing	20	10
Excess spread financing	519	768
Recurring Fair Value Measurements \| Level 3 \| IRLCs
Assets
Fair Value	21	134
Fair Value	8
Recurring Fair Value Measurements \| Level 3 \| LPCs
Assets
Fair Value	1	3
Fair Value	5	2
Recurring Fair Value Measurements \| Level 3 \| Forward MBS trades
Assets
Fair Value	0	0
Fair Value	0	0
Recurring Fair Value Measurements \| Level 3 \| Swap futures
Assets
Fair Value		$ 0
Recurring Fair Value Measurements \| Level 3 \| Treasury futures
Assets
Fair Value	$ 0

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Mortgage Servicing Rights Liability Resulting from Sale or Securitization of Servicer Advances, Rights not Accounted for as a Sale

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- Definition

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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- Definition

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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- Definition

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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