Loans - Credit Risk Profile of Commercial Loans (Detail) - USD ($) $ in Millions		Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total	[1]	$ 58,610	$ 55,864
Commercial loans:
Financing Receivable, Credit Quality Indicator [Line Items]
2022		844	3,735
2021		3,473	2,458
2020		2,336	3,778
2019		3,374	2,590
2018		2,454	1,184
Prior		12,764	11,747
Revolving Loans		16,997	14,071
Revolving Loans Converted to Term Loans		212	233
Total		42,454	39,796
Commercial loans: | Real Estate, including Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		315	969
2021		992	653
2020		622	2,516
2019		2,146	2,116
2018		1,936	593
Prior		1,937	1,325
Revolving Loans		56	46
Revolving Loans Converted to Term Loans		16	16
Total		8,020	8,234
Commercial loans: | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		197	1,630
2021		1,384	713
2020		646	608
2019		661	220
2018		213	238
Prior		4,697	4,757
Revolving Loans		7,311	5,575
Revolving Loans Converted to Term Loans		196	217
Total		15,305	13,958
Commercial loans: | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		322	547
2021		581	540
2020		525	203
2019		149	80
2018		100	243
Prior		4,963	4,620
Revolving Loans		5,308	4,876
Revolving Loans Converted to Term Loans		0	0
Total		11,948	11,109
Commercial loans: | Other commercial:
Financing Receivable, Credit Quality Indicator [Line Items]
2022		10	589
2021		516	552
2020		543	451
2019		418	174
2018		205	110
Prior		1,167	1,045
Revolving Loans		4,322	3,574
Revolving Loans Converted to Term Loans		0	0
Total		7,181	6,495
Commercial loans: | Investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
2022		548	1,532
2021		1,498	1,596
2020		1,455	1,073
2019		1,043	1,062
2018		1,241	404
Prior		7,793	7,223
Revolving Loans		12,079	10,277
Revolving Loans Converted to Term Loans		23	55
Total		25,680	23,222
Commercial loans: | Investment grade | Real Estate, including Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		165	1
2021		52	361
2020		367	491
2019		498	772
2018		913	57
Prior		297	248
Revolving Loans		23	12
Revolving Loans Converted to Term Loans		0	0
Total		2,315	1,942
Commercial loans: | Investment grade | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		64	881
2021		781	254
2020		336	240
2019		280	52
2018		41	43
Prior		2,409	2,122
Revolving Loans		3,217	2,498
Revolving Loans Converted to Term Loans		23	55
Total		7,151	6,145
Commercial loans: | Investment grade | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		312	530
2021		560	539
2020		292	189
2019		144	64
2018		82	235
Prior		4,110	3,910
Revolving Loans		4,713	4,240
Revolving Loans Converted to Term Loans		0	0
Total		10,213	9,707
Commercial loans: | Investment grade | Other commercial:
Financing Receivable, Credit Quality Indicator [Line Items]
2022		7	120
2021		105	442
2020		460	153
2019		121	174
2018		205	69
Prior		977	943
Revolving Loans		4,126	3,527
Revolving Loans Converted to Term Loans		0	0
Total		6,001	5,428
Commercial loans: | Non-investment grade
Financing Receivable, Credit Quality Indicator [Line Items]
2022		296	2,203
2021		1,975	862
2020		881	2,705
2019		2,331	1,528
2018		1,213	780
Prior		4,971	4,524
Revolving Loans		4,918	3,794
Revolving Loans Converted to Term Loans		189	178
Total		16,774	16,574
Commercial loans: | Non-investment grade | Real Estate, including Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2022		150	968
2021		940	292
2020		255	2,025
2019		1,648	1,344
2018		1,023	536
Prior		1,640	1,077
Revolving Loans		33	34
Revolving Loans Converted to Term Loans		16	16
Total		5,705	6,292
Commercial loans: | Non-investment grade | Business and corporate banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		133	749
2021		603	459
2020		310	368
2019		381	168
2018		172	195
Prior		2,288	2,635
Revolving Loans		4,094	3,077
Revolving Loans Converted to Term Loans		173	162
Total		8,154	7,813
Commercial loans: | Non-investment grade | Global banking
Financing Receivable, Credit Quality Indicator [Line Items]
2022		10	17
2021		21	1
2020		233	14
2019		5	16
2018		18	8
Prior		853	710
Revolving Loans		595	636
Revolving Loans Converted to Term Loans		0	0
Total		1,735	1,402
Commercial loans: | Non-investment grade | Other commercial:
Financing Receivable, Credit Quality Indicator [Line Items]
2022		3	469
2021		411	110
2020		83	298
2019		297	0
2018		0	41
Prior		190	102
Revolving Loans		196	47
Revolving Loans Converted to Term Loans		0	0
Total		$ 1,180	$ 1,067

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at March 31, 2022 and December 31, 2021. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. March 31, 2022December 31, 2021(in millions)AssetsLoans$128 $46 Other assets51 55 Total assets$179 $101 LiabilitiesInterest, taxes and other liabilities$31 $9 Total liabilities$31 $9