Loans - Schedule of Credit Quality Indicators for Term Loans by Origination Year (Detail) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Recorded Investment [Line Items]
Total	$ 181,515	$ 162,135
Percentage of total	100.00%	100.00%
All Classes except Consumer
Financing Receivable, Recorded Investment [Line Items]
Total	$ 147,617	$ 131,623
Corporate
Financing Receivable, Recorded Investment [Line Items]
Total	63,181	55,927
Financing receivable revolving converted to term loan	$ 1,250	$ 0
Investment-Grade
Financing Receivable, Recorded Investment [Line Items]
Percentage of total	42.00%	39.00%
Investment-Grade | All Classes except Consumer
Financing Receivable, Recorded Investment [Line Items]
Total	$ 62,336	$ 50,923
Non-Investment- Grade
Financing Receivable, Recorded Investment [Line Items]
Percentage of total	53.00%	57.00%
Non-Investment- Grade | All Classes except Consumer
Financing Receivable, Recorded Investment [Line Items]
Total	$ 78,212	$ 75,179
Other Metrics/ Unrated
Financing Receivable, Recorded Investment [Line Items]
Percentage of total	5.00%	4.00%
Other Metrics/ Unrated | All Classes except Consumer
Financing Receivable, Recorded Investment [Line Items]
Total	$ 7,069	$ 5,521
Corporate
Financing Receivable, Recorded Investment [Line Items]
2022	7,876	15,163
2021	10,878	6,479
2020	5,580	4,400
2019	3,658	4,743
2018	3,897	2,590
2017 or earlier	4,089	1,967
Revolving	21,453	15,618
Total	57,431	50,960
Corporate | Investment-Grade
Financing Receivable, Recorded Investment [Line Items]
2022	4,364	4,687
2021	3,847	1,911
2020	1,246	451
2019	325	1,842
2018	1,833	733
2017 or earlier	1,063	274
Revolving	7,259	3,800
Total	19,937	13,698
Corporate | Non-Investment- Grade
Financing Receivable, Recorded Investment [Line Items]
2022	3,512	10,424
2021	7,031	4,561
2020	4,334	3,949
2019	3,333	2,901
2018	2,064	1,857
2017 or earlier	3,026	1,693
Revolving	14,193	11,744
Total	37,493	37,129
Corporate | Other Metrics/ Unrated
Financing Receivable, Recorded Investment [Line Items]
2022	0	52
2021	0	7
2020	0	0
2019	0	0
2018	0	0
2017 or earlier	0	0
Revolving	1	74
Total	1	133
Wealth management
Financing Receivable, Recorded Investment [Line Items]
2022	3,559	3,856
2021	3,635	845
2020	899	889
2019	636	372
2018	392	411
2017 or earlier	1,154	808
Revolving	35,289	30,881
Total	45,564	38,062
Wealth management | Investment-Grade
Financing Receivable, Recorded Investment [Line Items]
2022	1,886	1,405
2021	1,391	558
2020	522	537
2019	411	334
2018	356	380
2017 or earlier	686	565
Revolving	30,018	26,349
Total	35,270	30,128
Wealth management | Non-Investment- Grade
Financing Receivable, Recorded Investment [Line Items]
2022	766	1,186
2021	1,069	287
2020	377	352
2019	225	38
2018	36	31
2017 or earlier	468	243
Revolving	2,083	2,127
Total	5,024	4,264
Wealth management | Other Metrics/ Unrated
Financing Receivable, Recorded Investment [Line Items]
2022	907	1,265
2021	1,175	0
2020	0	0
2019	0	0
2018	0	0
2017 or earlier	0	0
Revolving	3,188	2,405
Total	5,270	3,670
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
2022	3,249	4,512
2021	3,656	2,017
2020	1,505	1,388
2019	1,250	1,036
2018	672	1,022
2017 or earlier	1,335	995
Revolving	10,547	10,180
Total	22,214	21,150
Commercial real estate | Investment-Grade
Financing Receivable, Recorded Investment [Line Items]
2022	39	334
2021	219	127
2020	85	52
2019	47	207
2018	184	398
2017 or earlier	655	405
Revolving	863	1,768
Total	2,092	3,291
Commercial real estate | Non-Investment- Grade
Financing Receivable, Recorded Investment [Line Items]
2022	3,053	4,084
2021	3,437	1,890
2020	1,420	1,336
2019	1,203	829
2018	488	624
2017 or earlier	674	583
Revolving	9,684	8,412
Total	19,959	17,758
Commercial real estate | Other Metrics/ Unrated
Financing Receivable, Recorded Investment [Line Items]
2022	157	94
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017 or earlier	6	7
Revolving	0	0
Total	163	101
Residential real estate
Financing Receivable, Recorded Investment [Line Items]
2022	1,049	2,310
2021	1,578	920
2020	102	173
2019	101	249
2018	245	192
2017 or earlier	152	57
Revolving	10,857	11,592
Total	14,084	15,493
Residential real estate | Investment-Grade
Financing Receivable, Recorded Investment [Line Items]
2022	97	113
2021	141	260
2020	0	0
2019	0	0
2018	0	8
2017 or earlier	6	0
Revolving	669	673
Total	913	1,054
Residential real estate | Non-Investment- Grade
Financing Receivable, Recorded Investment [Line Items]
2022	734	1,944
2021	1,208	557
2020	11	0
2019	0	84
2018	103	65
2017 or earlier	2	1
Revolving	10,188	10,919
Total	12,246	13,570
Residential real estate | Other Metrics/ Unrated
Financing Receivable, Recorded Investment [Line Items]
2022	218	253
2021	229	103
2020	91	173
2019	101	165
2018	142	119
2017 or earlier	144	56
Revolving	0	0
Total	925	869
Other
Financing Receivable, Recorded Investment [Line Items]
2022	198	955
2021	716	437
2020	350	44
2019	24	30
2018	23	13
2017 or earlier	9
Revolving	7,004	4,479
Total	8,324	5,958
Other | Investment-Grade
Financing Receivable, Recorded Investment [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
2017 or earlier	0
Revolving	4,124	2,752
Total	4,124	2,752
Other | Non-Investment- Grade
Financing Receivable, Recorded Investment [Line Items]
2022	84	694
2021	556	59
2020	30	25
2019	11	30
2018	13	5
2017 or earlier	4
Revolving	2,792	1,645
Total	3,490	2,458
Other | Other Metrics/ Unrated
Financing Receivable, Recorded Investment [Line Items]
2022	114	261
2021	160	378
2020	320	19
2019	13	0
2018	10	8
2017 or earlier	5
Revolving	88	82
Total	$ 710	$ 748