Loans - Summary of Criticized Assets for Commercial Loans (Detail) - USD ($) $ in Millions		Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total	[1]	$ 61,798	$ 55,864
Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
2022		4,068	3,735
2021		3,066	2,458
2020		2,360	3,778
2019		3,429	2,590
2018		2,439	1,184
Prior		12,202	11,747
Revolving Loans		16,865	14,071
Revolving Loans Converted to Term Loans		266	233
Total		44,695	39,796
Commercial loans | Real estate, including construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		1,126	969
2021		1,085	653
2020		623	2,516
2019		2,179	2,116
2018		1,914	593
Prior		1,805	1,325
Revolving Loans		44	46
Revolving Loans Converted to Term Loans		15	16
Total		8,791	8,234
Commercial loans | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		484	1,630
2021		1,270	713
2020		574	608
2019		657	220
2018		233	238
Prior		4,789	4,757
Revolving Loans		7,850	5,575
Revolving Loans Converted to Term Loans		251	217
Total		16,108	13,958
Commercial loans | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		2,390	547
2021		553	540
2020		566	203
2019		178	80
2018		114	243
Prior		4,561	4,620
Revolving Loans		4,601	4,876
Revolving Loans Converted to Term Loans		0	0
Total		12,963	11,109
Commercial loans | Other commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2022		68	589
2021		158	552
2020		597	451
2019		415	174
2018		178	110
Prior		1,047	1,045
Revolving Loans		4,370	3,574
Revolving Loans Converted to Term Loans		0	0
Total		6,833	6,495
Commercial loans | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
2022		141	8
2021		855	20
2020		409	829
2019		653	841
2018		825	427
Prior		1,694	1,370
Revolving Loans		1,246	983
Revolving Loans Converted to Term Loans		43	19
Total		5,866	4,497
Commercial loans | Criticized | Real estate, including construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		107	0
2021		812	1
2020		95	702
2019		623	752
2018		768	398
Prior		1,265	773
Revolving Loans		20	20
Revolving Loans Converted to Term Loans		14	11
Total		3,704	2,657
Commercial loans | Criticized | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		34	0
2021		43	19
2020		90	127
2019		13	89
2018		57	29
Prior		300	528
Revolving Loans		794	613
Revolving Loans Converted to Term Loans		29	8
Total		1,360	1,413
Commercial loans | Criticized | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	8
2021		0	0
2020		224	0
2019		17	0
2018		0	0
Prior		126	62
Revolving Loans		423	310
Revolving Loans Converted to Term Loans		0	0
Total		790	380
Commercial loans | Criticized | 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	7
Revolving Loans		9	40
Revolving Loans Converted to Term Loans		0	0
Total		12	47
Commercial loans | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2022		141	8
2021		855	1
2020		123	441
2019		233	547
2018		29	116
Prior		494	548
Revolving Loans		376	220
Revolving Loans Converted to Term Loans		15	0
Total		2,266	1,881
Commercial loans | Special mention | Real estate, including construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		107	0
2021		812	0
2020		59	350
2019		233	487
2018		0	90
Prior		229	259
Revolving Loans		0	0
Revolving Loans Converted to Term Loans		3	0
Total		1,443	1,186
Commercial loans | Special mention | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		34	0
2021		43	1
2020		64	91
2019		0	60
2018		29	26
Prior		142	274
Revolving Loans		230	173
Revolving Loans Converted to Term Loans		12	0
Total		554	625
Commercial loans | Special mention | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	8
2021		0	0
2020		0	0
2019		0	0
2018		0	0
Prior		123	8
Revolving Loans		146	47
Revolving Loans Converted to Term Loans		0	0
Total		269	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		0	0
2021		0	19
2020		269	308
2019		344	272
2018		781	311
Prior		1,188	741
Revolving Loans		821	716
Revolving Loans Converted to Term Loans		28	19
Total		3,431	2,386
Commercial loans | Substandard | Real estate, including construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	0
2021		0	1
2020		36	272
2019		314	263
2018		768	308
Prior		1,025	461
Revolving Loans		20	20
Revolving Loans Converted to Term Loans		11	11
Total		2,174	1,336
Commercial loans | Substandard | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	0
2021		0	18
2020		9	36
2019		13	9
2018		13	3
Prior		157	226
Revolving Loans		538	424
Revolving Loans Converted to Term Loans		17	8
Total		747	724
Commercial loans | Substandard | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	0
2021		0	0
2020		224	0
2019		17	0
2018		0	0
Prior		3	54
Revolving Loans		254	232
Revolving Loans Converted to Term Loans		0	0
Total		498	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		9	40
Revolving Loans Converted to Term Loans		0	0
Total		12	40
Commercial loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	0
2021		0	0
2020		17	80
2019		76	22
2018		15	0
Prior		12	81
Revolving Loans		49	47
Revolving Loans Converted to Term Loans		0	0
Total		169	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		76	2
2018		0	0
Prior		11	53
Revolving Loans		0	0
Revolving Loans Converted to Term Loans		0	0
Total		87	135
Commercial loans | Doubtful | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		0	0
2021		0	0
2020		17	0
2019		0	20
2018		15	0
Prior		1	28
Revolving Loans		26	16
Revolving Loans Converted to Term Loans		0	0
Total		59	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		23	31
Revolving Loans Converted to Term Loans		0	0
Total		$ 23	$ 31

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at June 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. June 30, 2022December 31, 2021(in millions)AssetsLoans$118 $46 Other assets46 55 Total assets$164 $101 LiabilitiesInterest, taxes and other liabilities$28 $9 Total liabilities$28 $9