Loans Held-for-Investment - Loan Credit Quality Indicators (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment
Total loans held-for-investment	$ 13,408	$ 16,227
Consumer loans
Financing Receivable, Recorded Investment
2021	704
2020	433
2019	496
2018	209
2017	118
Prior	460
Revolving Loans Amortized Cost Basis	876
Revolving Loans Converted to Term Loans Amortized Cost Basis	72
Total	3,368	4,109
Total loans held-for-investment	3,385	4,126
Consumer loans | Residential first mortgage
Financing Receivable, Recorded Investment
Total loans held-for-investment	1,536	2,266
Consumer loans | Residential first mortgage | Debt-to-value ratio, greater than 90 percent
Financing Receivable, Recorded Investment
2021	88
2020	74
2019	142
2018	53
2017	16
Prior	16
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	389
Consumer loans | Residential first mortgage | Debt-to-value ratio, 71 to 90 percent
Financing Receivable, Recorded Investment
2021	109
2020	78
2019	58
2018	29
2017	31
Prior	185
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	490
Consumer loans | Residential first mortgage | Debt-to-value ratio, 55 to 70 percent
Financing Receivable, Recorded Investment
2021	69
2020	26
2019	27
2018	9
2017	36
Prior	163
Revolving Loans Amortized Cost Basis	2
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	332
Consumer loans | Residential first mortgage | Debt-to-value ratio, less than 55 percent
Financing Receivable, Recorded Investment
2021	53
2020	23
2019	25
2018	9
2017	31
Prior	75
Revolving Loans Amortized Cost Basis	80
Revolving Loans Converted to Term Loans Amortized Cost Basis	14
Total	310
Consumer loans | Residential first mortgage | FICO score, greater than 750
Financing Receivable, Recorded Investment
2021	139
2020	94
2019	107
2018	40
2017	70
Prior	212
Revolving Loans Amortized Cost Basis	49
Revolving Loans Converted to Term Loans Amortized Cost Basis	5
Total	716
Consumer loans | Residential first mortgage | FICO score, 700 to 750
Financing Receivable, Recorded Investment
2021	117
2020	58
2019	69
2018	36
2017	36
Prior	161
Revolving Loans Amortized Cost Basis	22
Revolving Loans Converted to Term Loans Amortized Cost Basis	6
Total	505
Consumer loans | Residential first mortgage | FICO score, less than 700
Financing Receivable, Recorded Investment
2021	63
2020	49
2019	76
2018	24
2017	8
Prior	66
Revolving Loans Amortized Cost Basis	11
Revolving Loans Converted to Term Loans Amortized Cost Basis	3
Total	300
Consumer loans | Residential first mortgage | Pass
Financing Receivable, Recorded Investment
2021	318
2020	197
2019	233
2018	89
2017	108
Prior	407
Revolving Loans Amortized Cost Basis	82
Revolving Loans Converted to Term Loans Amortized Cost Basis	10
Total	1,444	2,205
Consumer loans | Residential first mortgage | Watch
Financing Receivable, Recorded Investment
2021	0
2020	1
2019	12
2018	3
2017	4
Prior	11
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	3
Total	34	21
Consumer loans | Residential first mortgage | Substandard
Financing Receivable, Recorded Investment
2021	1
2020	3
2019	7
2018	8
2017	2
Prior	21
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	1
Total	43	25
Consumer loans | Home equity
Financing Receivable, Recorded Investment
Total loans held-for-investment	613	856
Consumer loans | Home equity | Debt-to-value ratio, greater than 90 percent
Financing Receivable, Recorded Investment
2021	0
2020	0
2019	0
2018	0
2017	1
Prior	7
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	8
Consumer loans | Home equity | Debt-to-value ratio, 71 to 90 percent
Financing Receivable, Recorded Investment
2021	3
2020	3
2019	11
2018	4
2017	1
Prior	6
Revolving Loans Amortized Cost Basis	369
Revolving Loans Converted to Term Loans Amortized Cost Basis	35
Total	432
Consumer loans | Home equity | Debt-to-value ratio, less than or equal to 70 percent
Financing Receivable, Recorded Investment
2021	1
2020	1
2019	4
2018	2
2017	1
Prior	3
Revolving Loans Amortized Cost Basis	141
Revolving Loans Converted to Term Loans Amortized Cost Basis	18
Total	171
Consumer loans | Home equity | FICO score, greater than 750
Financing Receivable, Recorded Investment
2021	2
2020	2
2019	4
2018	2
2017	1
Prior	4
Revolving Loans Amortized Cost Basis	238
Revolving Loans Converted to Term Loans Amortized Cost Basis	13
Total	266
Consumer loans | Home equity | FICO score, 700 to 750
Financing Receivable, Recorded Investment
2021	2
2020	1
2019	6
2018	2
2017	1
Prior	6
Revolving Loans Amortized Cost Basis	210
Revolving Loans Converted to Term Loans Amortized Cost Basis	22
Total	250
Consumer loans | Home equity | FICO score, less than 700
Financing Receivable, Recorded Investment
2021	0
2020	1
2019	5
2018	2
2017	1
Prior	6
Revolving Loans Amortized Cost Basis	62
Revolving Loans Converted to Term Loans Amortized Cost Basis	18
Total	95
Consumer loans | Home equity | Pass
Financing Receivable, Recorded Investment
2021	4
2020	4
2019	15
2018	6
2017	3
Prior	15
Revolving Loans Amortized Cost Basis	508
Revolving Loans Converted to Term Loans Amortized Cost Basis	49
Total	604	838
Consumer loans | Home equity | Watch
Financing Receivable, Recorded Investment
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	1
Total	1	13
Consumer loans | Home equity | Substandard
Financing Receivable, Recorded Investment
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	1
Revolving Loans Amortized Cost Basis	2
Revolving Loans Converted to Term Loans Amortized Cost Basis	3
Total	6	3
Consumer loans | Other consumer | FICO score, greater than 750
Financing Receivable, Recorded Investment
2021	251
2020	162
2019	142
2018	56
2017	1
Prior	4
Revolving Loans Amortized Cost Basis	273
Revolving Loans Converted to Term Loans Amortized Cost Basis	3
Total	892
Consumer loans | Other consumer | FICO score, 700 to 750
Financing Receivable, Recorded Investment
2021	128
2020	62
2019	79
2018	39
2017	0
Prior	1
Revolving Loans Amortized Cost Basis	7
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	316
Consumer loans | Other consumer | FICO score, less than 700
Financing Receivable, Recorded Investment
2021	2
2020	4
2019	8
2018	8
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	4
Revolving Loans Converted to Term Loans Amortized Cost Basis	2
Total	28
Consumer loans | Other consumer | Pass
Financing Receivable, Recorded Investment
2021	380
2020	227
2019	226
2018	101
2017	1
Prior	5
Revolving Loans Amortized Cost Basis	284
Revolving Loans Converted to Term Loans Amortized Cost Basis	5
Total	1,229	1,000
Consumer loans | Other consumer | Watch
Financing Receivable, Recorded Investment
2021	0
2020	0
2019	1
2018	1
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	2	1
Consumer loans | Other consumer | Substandard
Financing Receivable, Recorded Investment
2021	1
2020	1
2019	2
2018	1
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total	5	3
Consumer loans | Residential first mortgage and home equity
Financing Receivable, Recorded Investment
2021	323
2020	205
2019	267
2018	106
2017	117
Prior	455
Revolving Loans Amortized Cost Basis	592
Revolving Loans Converted to Term Loans Amortized Cost Basis	67
Total	2,132
Commercial loans
Financing Receivable, Recorded Investment
2021	5,755
2020	347
2019	744
2018	383
2017	421
Prior	444
Revolving Loans Amortized Cost Basis	1,929
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	10,023	12,101
Commercial loans | Commercial real estate
Financing Receivable, Recorded Investment
Total loans held-for-investment	3,223	3,061
Commercial loans | Commercial real estate | Pass
Financing Receivable, Recorded Investment
2021	518
2020	257
2019	558
2018	313
2017	238
Prior	402
Revolving Loans Amortized Cost Basis	785
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	3,071	2,805
Commercial loans | Commercial real estate | Watch
Financing Receivable, Recorded Investment
2021	2
2020	5
2019	1
2018	13
2017	64
Prior	35
Revolving Loans Amortized Cost Basis	8
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	128	166
Commercial loans | Commercial real estate | Special mention
Financing Receivable, Recorded Investment
2021	0
2020	0
2019	2
2018	0
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	2	53
Commercial loans | Commercial real estate | Substandard
Financing Receivable, Recorded Investment
2021	0
2020	0
2019	0
2018	0
2017	22
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	22	37
Commercial loans | Commercial and industrial
Financing Receivable, Recorded Investment
Total loans held-for-investment	1,826	1,382
Commercial loans | Commercial and industrial | Pass
Financing Receivable, Recorded Investment
2021	257
2020	81
2019	156
2018	30
2017	95
Prior	7
Revolving Loans Amortized Cost Basis	1,059
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	1,685	1,200
Commercial loans | Commercial and industrial | Watch
Financing Receivable, Recorded Investment
2021	4
2020	4
2019	10
2018	9
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	44
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	71	106
Commercial loans | Commercial and industrial | Special mention
Financing Receivable, Recorded Investment
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	0	24
Commercial loans | Commercial and industrial | Substandard
Financing Receivable, Recorded Investment
2021	0
2020	0
2019	17
2018	18
2017	2
Prior	0
Revolving Loans Amortized Cost Basis	33
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	70	52
Commercial loans | Warehouse | Pass
Financing Receivable, Recorded Investment
2021	4,834
2020	0
2019	0
2018	0
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	4,834	7,398
Commercial loans | Warehouse | Watch
Financing Receivable, Recorded Investment
2021	140
2020	0
2019	0
2018	0
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	140	260
Commercial loans | Warehouse | Special mention
Financing Receivable, Recorded Investment
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	0	0
Commercial loans | Warehouse | Substandard
Financing Receivable, Recorded Investment
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term Loans Amortized Cost Basis	0
Total loans held-for-investment	$ 0	$ 0