Loans - Summary of Criticized Assets for Commercial Loans (Detail) - USD ($) $ in Millions		Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total	[1]	$ 61,775	$ 55,864
Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
2022		4,591	3,735
2021		2,929	2,458
2020		2,060	3,778
2019		3,300	2,590
2018		2,360	1,184
Prior		12,286	11,747
Revolving Loans		16,699	14,071
Revolving Loans Converted to Term Loans		242	233
Total		44,467	39,796
Commercial loans | Real estate, including construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		1,271	969
2021		909	653
2020		629	2,516
2019		1,976	2,116
2018		1,825	593
Prior		1,737	1,325
Revolving Loans		44	46
Revolving Loans Converted to Term Loans		4	16
Total		8,395	8,234
Commercial loans | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		1,017	1,630
2021		1,260	713
2020		402	608
2019		764	220
2018		230	238
Prior		5,036	4,757
Revolving Loans		7,783	5,575
Revolving Loans Converted to Term Loans		238	217
Total		16,730	13,958
Commercial loans | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		2,184	547
2021		454	540
2020		427	203
2019		150	80
2018		129	243
Prior		4,481	4,620
Revolving Loans		4,317	4,876
Revolving Loans Converted to Term Loans		0	0
Total		12,142	11,109
Commercial loans | Other commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2022		119	589
2021		306	552
2020		602	451
2019		410	174
2018		176	110
Prior		1,032	1,045
Revolving Loans		4,555	3,574
Revolving Loans Converted to Term Loans		0	0
Total		7,200	6,495
Commercial loans | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2022		567	8
2021		686	20
2020		158	829
2019		556	841
2018		704	427
Prior		1,353	1,370
Revolving Loans		1,172	983
Revolving Loans Converted to Term Loans		20	19
Total		5,216	4,497
Commercial loans | Criticized | Real estate, including construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		206	0
2021		616	1
2020		101	702
2019		526	752
2018		677	398
Prior		1,059	773
Revolving Loans		19	20
Revolving Loans Converted to Term Loans		3	11
Total		3,207	2,657
Commercial loans | Criticized | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		54	0
2021		70	19
2020		57	127
2019		13	89
2018		27	29
Prior		281	528
Revolving Loans		682	613
Revolving Loans Converted to Term Loans		17	8
Total		1,201	1,413
Commercial loans | Criticized | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		296	8
2021		0	0
2020		0	0
2019		17	0
2018		0	0
Prior		10	62
Revolving Loans		463	310
Revolving Loans Converted to Term Loans		0	0
Total		786	380
Commercial loans | Criticized | Other commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2022		11	0
2021		0	0
2020		0	0
2019		0	0
2018		0	0
Prior		3	7
Revolving Loans		8	40
Revolving Loans Converted to Term Loans		0	0
Total		22	47
Commercial loans | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2022		280	8
2021		616	1
2020		26	441
2019		213	547
2018		4	116
Prior		145	548
Revolving Loans		402	220
Revolving Loans Converted to Term Loans		15	0
Total		1,701	1,881
Commercial loans | Special mention | Real estate, including construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		205	0
2021		616	0
2020		22	350
2019		212	487
2018		0	90
Prior		20	259
Revolving Loans		0	0
Revolving Loans Converted to Term Loans		3	0
Total		1,078	1,186
Commercial loans | Special mention | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		22	0
2021		0	1
2020		4	91
2019		1	60
2018		4	26
Prior		117	274
Revolving Loans		181	173
Revolving Loans Converted to Term Loans		12	0
Total		341	625
Commercial loans | Special mention | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		53	8
2021		0	0
2020		0	0
2019		0	0
2018		0	0
Prior		8	8
Revolving Loans		221	47
Revolving Loans Converted to Term Loans		0	0
Total		282	63
Commercial loans | Special mention | Other commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2022			0
2021			0
2020			0
2019			0
2018			0
Prior			7
Revolving Loans			0
Revolving Loans Converted to Term Loans			0
Total			7
Commercial loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2022		276	0
2021		70	19
2020		105	308
2019		268	272
2018		685	311
Prior		1,197	741
Revolving Loans		733	716
Revolving Loans Converted to Term Loans		1	19
Total		3,335	2,386
Commercial loans | Substandard | Real estate, including construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		1	0
2021		0	1
2020		79	272
2019		239	263
2018		677	308
Prior		1,029	461
Revolving Loans		19	20
Revolving Loans Converted to Term Loans		0	11
Total		2,044	1,336
Commercial loans | Substandard | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		32	0
2021		70	18
2020		26	36
2019		12	9
2018		8	3
Prior		163	226
Revolving Loans		479	424
Revolving Loans Converted to Term Loans		1	8
Total		791	724
Commercial loans | Substandard | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		243	0
2021		0	0
2020		0	0
2019		17	0
2018		0	0
Prior		2	54
Revolving Loans		227	232
Revolving Loans Converted to Term Loans		0	0
Total		489	286
Commercial loans | Substandard | Other commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	0
2021		0	0
2020		0	0
2019		0	0
2018		0	0
Prior		3	0
Revolving Loans		8	40
Revolving Loans Converted to Term Loans		0	0
Total		11	40
Commercial loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2022		11	0
2021		0	0
2020		27	80
2019		75	22
2018		15	0
Prior		11	81
Revolving Loans		37	47
Revolving Loans Converted to Term Loans		4	0
Total		180	230
Commercial loans | Doubtful | Real estate, including construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	0
2021		0	0
2020		0	80
2019		75	2
2018		0	0
Prior		10	53
Revolving Loans		0	0
Revolving Loans Converted to Term Loans		0	0
Total		85	135
Commercial loans | Doubtful | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	0
2021		0	0
2020		27	0
2019		0	20
2018		15	0
Prior		1	28
Revolving Loans		22	16
Revolving Loans Converted to Term Loans		4	0
Total		69	64
Commercial loans | Doubtful | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	0
2021		0	0
2020		0	0
2019		0	0
2018		0	0
Prior		0	0
Revolving Loans		15	31
Revolving Loans Converted to Term Loans		0	0
Total		15	$ 31
Commercial loans | Doubtful | Other commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2022		11
2021		0
2020		0
2019		0
2018		0
Prior		0
Revolving Loans		0
Revolving Loans Converted to Term Loans		0
Total		$ 11

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at September 30, 2022 and December 31, 2021. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. September 30, 2022December 31, 2021(in millions)AssetsLoans$127 $46 Other assets44 55 Total assets$171 $101 LiabilitiesInterest, taxes and other liabilities$26 $9 Total liabilities$26 $9