Fair Value Measurements - Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Assets
Mortgage loans held for sale	$ 2,072	$ 4,381
Liabilities
Mortgage servicing rights financing	24	10
Recurring Fair Value Measurements
Assets
Mortgage loans held for sale	2,072	4,381
Mortgage servicing rights	6,151	4,223
Equity securities	59	63
Liabilities
Mortgage servicing rights financing	24	10
Excess spread financing	532	768
Recurring Fair Value Measurements \| IRLCs
Assets
Derivative financial instruments	62	134
Liabilities
Fair Value	1
Recurring Fair Value Measurements \| LPCs
Assets
Derivative financial instruments	3	3
Liabilities
Fair Value	1	2
Recurring Fair Value Measurements \| Forward MBS trades
Assets
Derivative financial instruments	12	7
Liabilities
Fair Value	13	8
Recurring Fair Value Measurements \| Swap futures
Liabilities
Fair Value		6
Recurring Fair Value Measurements \| Treasury futures
Liabilities
Fair Value	18
Recurring Fair Value Measurements \| Level 1
Assets
Mortgage loans held for sale	0	0
Mortgage servicing rights	0	0
Equity securities	5	9
Liabilities
Mortgage servicing rights financing	0	0
Excess spread financing	0	0
Recurring Fair Value Measurements \| Level 1 \| IRLCs
Assets
Derivative financial instruments	0	0
Liabilities
Fair Value	0
Recurring Fair Value Measurements \| Level 1 \| LPCs
Assets
Derivative financial instruments	0	0
Liabilities
Fair Value	0	0
Recurring Fair Value Measurements \| Level 1 \| Forward MBS trades
Assets
Derivative financial instruments	0	0
Liabilities
Fair Value	0	0
Recurring Fair Value Measurements \| Level 1 \| Swap futures
Liabilities
Fair Value		0
Recurring Fair Value Measurements \| Level 1 \| Treasury futures
Liabilities
Fair Value	0
Recurring Fair Value Measurements \| Level 2
Assets
Mortgage loans held for sale	2,072	4,381
Mortgage servicing rights	0	0
Equity securities	0	0
Liabilities
Mortgage servicing rights financing	0	0
Excess spread financing	0	0
Recurring Fair Value Measurements \| Level 2 \| IRLCs
Assets
Derivative financial instruments	0	0
Liabilities
Fair Value	0
Recurring Fair Value Measurements \| Level 2 \| LPCs
Assets
Derivative financial instruments	0	0
Liabilities
Fair Value	0	0
Recurring Fair Value Measurements \| Level 2 \| Forward MBS trades
Assets
Derivative financial instruments	12	7
Liabilities
Fair Value	13	8
Recurring Fair Value Measurements \| Level 2 \| Swap futures
Liabilities
Fair Value		6
Recurring Fair Value Measurements \| Level 2 \| Treasury futures
Liabilities
Fair Value	18
Recurring Fair Value Measurements \| Level 3
Assets
Mortgage loans held for sale	0	0
Mortgage servicing rights	6,151	4,223
Equity securities	54	54
Liabilities
Mortgage servicing rights financing	24	10
Excess spread financing	532	768
Recurring Fair Value Measurements \| Level 3 \| IRLCs
Assets
Derivative financial instruments	62	134
Liabilities
Fair Value	1
Recurring Fair Value Measurements \| Level 3 \| LPCs
Assets
Derivative financial instruments	3	3
Liabilities
Fair Value	1	2
Recurring Fair Value Measurements \| Level 3 \| Forward MBS trades
Assets
Derivative financial instruments	0	0
Liabilities
Fair Value	0	0
Recurring Fair Value Measurements \| Level 3 \| Swap futures
Liabilities
Fair Value		$ 0
Recurring Fair Value Measurements \| Level 3 \| Treasury futures
Liabilities
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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Fair value, before effects of master netting arrangements, of a 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. Includes assets elected not to be offset. Excludes assets 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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