Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Assets
Investment securities available-for-sale	$ 2,346	$ 1,804
Loans held-for-sale	3,181	4,920
Loans held-for-investment	21	16
Mortgage servicing rights	622	392
Total assets at fair value	3,202	4,936
Agency - Commercial
Assets
Investment securities available-for-sale	1,486	747
Agency - Residential
Assets
Investment securities available-for-sale	561	696
Municipal obligations
Assets
Investment securities available-for-sale	16	20
Corporate debt obligations
Assets
Investment securities available-for-sale	57	73
Certificate of deposit
Assets
Investment securities available-for-sale	1	1
Estimate of Fair Value Measurement
Assets
Investment securities available-for-sale	2,346	1,804
Loans held-for-sale	3,482	5,054
Loans held-for-investment	14,523	13,453
Mortgage servicing rights	622	392
Level 1 \| Estimate of Fair Value Measurement
Assets
Investment securities available-for-sale	0	0
Loans held-for-sale	0	0
Loans held-for-investment	0	0
Mortgage servicing rights	0	0
Level 2 \| Estimate of Fair Value Measurement
Assets
Investment securities available-for-sale	2,346	1,804
Loans held-for-sale	3,482	5,054
Loans held-for-investment	21	14
Mortgage servicing rights	0	0
Level 3 \| Estimate of Fair Value Measurement
Assets
Investment securities available-for-sale	0	0
Loans held-for-sale	0	0
Loans held-for-investment	14,502	13,439
Mortgage servicing rights	622	392
Recurring \| Estimate of Fair Value Measurement
Assets
Mortgage servicing rights	622	392
Total assets at fair value	6,432	7,273
Liabilities
Total liabilities at fair value	(81)	(20)
Recurring \| Estimate of Fair Value Measurement \| Rate lock commitments
Assets
Derivative assets	34	54
Liabilities
Derivative liabilities	(9)	(1)
Recurring \| Estimate of Fair Value Measurement \| Futures
Assets
Derivative assets	2
Recurring \| Estimate of Fair Value Measurement \| Mortgage-backed securities forwards
Assets
Derivative assets	43	10
Liabilities
Derivative liabilities	(31)	(14)
Recurring \| Estimate of Fair Value Measurement \| Interest rate swaps and swaptions
Assets
Derivative assets	183	77
Liabilities
Derivative liabilities		(5)
Recurring \| Estimate of Fair Value Measurement \| Interest rate swaps
Liabilities
Derivative liabilities	(41)
Recurring \| Estimate of Fair Value Measurement \| Residential first mortgage loans
Assets
Loans held-for-sale	3,181	4,920
Loans held-for-investment	21	15
Recurring \| Estimate of Fair Value Measurement \| Home equity
Assets
Loans held-for-investment		1
Recurring \| Estimate of Fair Value Measurement \| Agency - Commercial
Assets
Investment securities available-for-sale	1,486	747
Recurring \| Estimate of Fair Value Measurement \| Agency - Residential
Assets
Investment securities available-for-sale	561	696
Recurring \| Estimate of Fair Value Measurement \| Municipal obligations
Assets
Investment securities available-for-sale	16	20
Recurring \| Estimate of Fair Value Measurement \| Corporate debt obligations
Assets
Investment securities available-for-sale	57	73
Recurring \| Estimate of Fair Value Measurement \| Other MBS
Assets
Investment securities available-for-sale	225	267
Recurring \| Estimate of Fair Value Measurement \| Certificate of deposit
Assets
Investment securities available-for-sale	1	1
Recurring \| Level 1
Assets
Mortgage servicing rights	0	0
Total assets at fair value	0	0
Liabilities
Total liabilities at fair value	0	0
Recurring \| Level 1 \| Rate lock commitments
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring \| Level 1 \| Futures
Assets
Derivative assets	0
Recurring \| Level 1 \| Mortgage-backed securities forwards
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring \| Level 1 \| Interest rate swaps and swaptions
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities		0
Recurring \| Level 1 \| Interest rate swaps
Liabilities
Derivative liabilities	0
Recurring \| Level 1 \| Residential first mortgage loans
Assets
Loans held-for-sale	0	0
Loans held-for-investment	0	0
Recurring \| Level 1 \| Home equity
Assets
Loans held-for-investment		0
Recurring \| Level 1 \| Agency - Commercial
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 1 \| Agency - Residential
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 1 \| Municipal obligations
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 1 \| Corporate debt obligations
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 1 \| Other MBS
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 1 \| Certificate of deposit
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 2
Assets
Mortgage servicing rights	0	0
Total assets at fair value	5,776	6,826
Liabilities
Total liabilities at fair value	(72)	(19)
Recurring \| Level 2 \| Rate lock commitments
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring \| Level 2 \| Futures
Assets
Derivative assets	2
Recurring \| Level 2 \| Mortgage-backed securities forwards
Assets
Derivative assets	43	10
Liabilities
Derivative liabilities	(31)	(14)
Recurring \| Level 2 \| Interest rate swaps and swaptions
Assets
Derivative assets	183	77
Liabilities
Derivative liabilities		(5)
Recurring \| Level 2 \| Interest rate swaps
Liabilities
Derivative liabilities	(41)
Recurring \| Level 2 \| Residential first mortgage loans
Assets
Loans held-for-sale	3,181	4,920
Loans held-for-investment	21	15
Recurring \| Level 2 \| Home equity
Assets
Loans held-for-investment		0
Recurring \| Level 2 \| Agency - Commercial
Assets
Investment securities available-for-sale	1,486	747
Recurring \| Level 2 \| Agency - Residential
Assets
Investment securities available-for-sale	561	696
Recurring \| Level 2 \| Municipal obligations
Assets
Investment securities available-for-sale	16	20
Recurring \| Level 2 \| Corporate debt obligations
Assets
Investment securities available-for-sale	57	73
Recurring \| Level 2 \| Other MBS
Assets
Investment securities available-for-sale	225	267
Recurring \| Level 2 \| Certificate of deposit
Assets
Investment securities available-for-sale	1	1
Recurring \| Level 3
Assets
Mortgage servicing rights	622	392
Total assets at fair value	656	447
Liabilities
Total liabilities at fair value	(9)	(1)
Recurring \| Level 3 \| Rate lock commitments
Assets
Derivative assets	34	54
Liabilities
Derivative liabilities	(9)	(1)
Recurring \| Level 3 \| Futures
Assets
Derivative assets	0
Recurring \| Level 3 \| Mortgage-backed securities forwards
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities	0	0
Recurring \| Level 3 \| Interest rate swaps and swaptions
Assets
Derivative assets	0	0
Liabilities
Derivative liabilities		0
Recurring \| Level 3 \| Interest rate swaps
Liabilities
Derivative liabilities	0
Recurring \| Level 3 \| Residential first mortgage loans
Assets
Loans held-for-sale	0	0
Loans held-for-investment	0	0
Recurring \| Level 3 \| Home equity
Assets
Loans held-for-investment		1
Recurring \| Level 3 \| Agency - Commercial
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 3 \| Agency - Residential
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 3 \| Municipal obligations
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 3 \| Corporate debt obligations
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 3 \| Other MBS
Assets
Investment securities available-for-sale	0	0
Recurring \| Level 3 \| Certificate of deposit
Assets
Investment securities available-for-sale	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value of financial and nonfinancial obligations.

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