Business Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 1,961	$ 700	$ 2,811	$ 1,349
Provision for credit losses	151	42	934	506
Net interest income (expense) after provision for credit losses	1,810	658	1,877	843
Noninterest income	658	424	10,917	1,274
Income (loss) before income taxes	896	337	10,367	562
Income tax expense (benefit)	214	82	167	36
Net income (loss)	682	255	10,200	526
Loans and leases	133,015	67,735	133,015	67,735	$ 70,781
Deposits	141,164	89,329	141,164	89,329	89,408
Operating lease equipment, net	8,531	7,971	8,531	7,971	$ 8,156
Operating Segments | General Banking
Segment Reporting Information [Line Items]
Net interest income (expense)	603	467	1,163	904
Provision for credit losses	29	7	43	(8)
Net interest income (expense) after provision for credit losses	574	460	1,120	912
Noninterest income	119	125	235	248
Noninterest expense	393	390	788	799
Income (loss) before income taxes	300	195	567	361
Income tax expense (benefit)	73	40	138	80
Net income (loss)	227	155	429	281
Loans and leases	44,719	40,159	44,719	40,159
Deposits	95,323	83,518	95,323	83,518
Operating lease equipment, net	0	0	0	0
Operating Segments | Commercial Banking
Segment Reporting Information [Line Items]
Net interest income (expense)	258	204	498	411
Provision for credit losses	170	35	219	1
Net interest income (expense) after provision for credit losses	88	169	279	410
Noninterest income	139	130	282	242
Noninterest expense	188	180	399	371
Income (loss) before income taxes	39	119	162	281
Income tax expense (benefit)	11	24	40	65
Net income (loss)	28	95	122	216
Loans and leases	29,433	27,505	29,433	27,505
Deposits	3,064	4,466	3,064	4,466
Operating lease equipment, net	741	724	741	724
Operating Segments | Silicon Valley Banking
Segment Reporting Information [Line Items]
Net interest income (expense)	635	0	700	0
Provision for credit losses	(47)	0	(47)	0
Net interest income (expense) after provision for credit losses	682	0	747	0
Noninterest income	169	0	183	0
Noninterest expense	592	0	625	0
Income (loss) before income taxes	259	0	305	0
Income tax expense (benefit)	70	0	81	0
Net income (loss)	189	0	224	0
Loans and leases	58,799	0	58,799	0
Deposits	40,860	0	40,860	0
Operating lease equipment, net	0	0	0	0
Operating Segments | Rail
Segment Reporting Information [Line Items]
Net interest income (expense)	(33)	(18)	(61)	(37)
Provision for credit losses	0	0	0	0
Net interest income (expense) after provision for credit losses	(33)	(18)	(61)	(37)
Noninterest income	178	160	355	322
Noninterest expense	121	111	241	211
Income (loss) before income taxes	24	31	53	74
Income tax expense (benefit)	6	7	13	18
Net income (loss)	18	24	40	56
Loans and leases	64	71	64	71
Deposits	11	11	11	11
Operating lease equipment, net	7,790	7,247	7,790	7,247
Corporate
Segment Reporting Information [Line Items]
Net interest income (expense)	498	47	511	71
Provision for credit losses	(1)	0	719	513
Net interest income (expense) after provision for credit losses	499	47	(208)	(442)
Noninterest income	53	9	9,862	462
Noninterest expense	278	64	374	174
Income (loss) before income taxes	274	(8)	9,280	(154)
Income tax expense (benefit)	54	11	(105)	(127)
Net income (loss)	220	(19)	9,385	(27)
Loans and leases	0	0	0	0
Deposits	1,906	1,334	1,906	1,334
Operating lease equipment, net	$ 0	$ 0	$ 0	$ 0