Business Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 850	$ 649
Provision (benefit) for credit losses	783	464
Net interest income (expense) after provision for credit losses	67	185
Noninterest income	10,259	850
Income (loss) before income taxes	9,471	225
Income tax expense (benefit)	(47)	(46)
Net income (loss)	9,518	271
Loans and leases	138,288	65,524	$ 70,781
Deposits	140,050	91,597	89,408
Operating lease equipment, net	8,331	7,972	$ 8,156
Operating Segments | General Banking
Segment Reporting Information [Line Items]
Net interest income (expense)	560	437
Provision (benefit) for credit losses	14	(15)
Net interest income (expense) after provision for credit losses	546	452
Noninterest income	116	123
Noninterest expense	395	409
Income (loss) before income taxes	267	166
Income tax expense (benefit)	65	40
Net income (loss)	202	126
Loans and leases	43,353	38,528
Deposits	85,982	85,458
Operating lease equipment, net	0	0
Operating Segments | Commercial Banking
Segment Reporting Information [Line Items]
Net interest income (expense)	240	207
Provision (benefit) for credit losses	49	(34)
Net interest income (expense) after provision for credit losses	191	241
Noninterest income	143	112
Noninterest expense	211	191
Income (loss) before income taxes	123	162
Income tax expense (benefit)	29	41
Net income (loss)	94	121
Loans and leases	28,684	26,922
Deposits	3,045	4,698
Operating lease equipment, net	719	721
Operating Segments | Silicon Valley Banking
Segment Reporting Information [Line Items]
Net interest income (expense)	65	0
Provision (benefit) for credit losses	0	0
Net interest income (expense) after provision for credit losses	65	0
Noninterest income	14	0
Noninterest expense	33	0
Income (loss) before income taxes	46	0
Income tax expense (benefit)	11	0
Net income (loss)	35	0
Loans and leases	66,171	0
Deposits	49,259	0
Operating lease equipment, net	0	0
Operating Segments | Rail
Segment Reporting Information [Line Items]
Net interest income (expense)	(28)	(19)
Provision (benefit) for credit losses	0	0
Net interest income (expense) after provision for credit losses	(28)	(19)
Noninterest income	177	162
Noninterest expense	120	100
Income (loss) before income taxes	29	43
Income tax expense (benefit)	7	11
Net income (loss)	22	32
Loans and leases	80	67
Deposits	14	13
Operating lease equipment, net	7,612	7,251
Corporate
Segment Reporting Information [Line Items]
Net interest income (expense)	13	24
Provision (benefit) for credit losses	720	513
Net interest income (expense) after provision for credit losses	(707)	(489)
Noninterest income	9,809	453
Noninterest expense	96	110
Income (loss) before income taxes	9,006	(146)
Income tax expense (benefit)	(159)	(138)
Net income (loss)	9,165	(8)
Loans and leases	0	7
Deposits	1,750	1,428
Operating lease equipment, net	$ 0	$ 0