Business Segments - Summary on Reconciliation of Results Under IFRS to US GAAP (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	[1]
Operating Statistics [Line Items]
Net interest income (expense)	$ 434		$ 532	$ 917		$ 1,009
Other operating income	448		343	901		829
Total operating income	882		875	1,818		1,838
Provision for credit losses	36		69	56		80
Total income	846		806	1,762		1,758
Operating expenses	647		693	1,276		1,379
Income before income tax	199		113	486		379
Total assets	166,928	[1]	171,232	166,928	[1]	171,232	$ 164,655
Total loans, net	57,340	[1]	61,264	57,340	[1]	61,264	58,796
Goodwill	458	[1]	458	458	[1]	458	458
Total deposits	121,636	[1]	127,263	121,636	[1]	127,263	$ 123,223
Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	502		500	1,045		945
Other operating income	404		377	790		905
Total operating income (expense)	906		877	1,835		1,850
Expected credit losses / provision for credit losses	33		46	62		21
Total income	873		831	1,773		1,829
Operating expenses	472		671	1,051		1,336
Profit (loss) before income tax	401		160	722		493
Total assets	185,329		192,198	185,329		192,198
Total loans, net	56,147		59,887	56,147		59,887
Goodwill	358		358	358		358
Total deposits	118,105		122,162	118,105		122,162
Group Reporting Basis Adjustments
Operating Statistics [Line Items]
Net interest income (expense)	2		0	3		1
Other operating income	(42)		(11)	(49)		(31)
Total operating income (expense)	(40)		(11)	(46)		(30)
Expected credit losses / provision for credit losses	3		23	(6)		59
Total income	(43)		(34)	(40)		(89)
Operating expenses	159		13	196		25
Profit (loss) before income tax	(202)		(47)	(236)		(114)
Total assets	(18,401)		(20,966)	(18,401)		(20,966)
Total loans, net	(144)		(890)	(144)		(890)
Goodwill	100		100	100		100
Total deposits	(2,575)		(3,434)	(2,575)		(3,434)
Group Reporting Basis Reclassifications
Operating Statistics [Line Items]
Net interest income (expense)	(70)		32	(131)		63
Other operating income	86		(23)	160		(45)
Total operating income (expense)	16		9	29		18
Expected credit losses / provision for credit losses	0		0	0		0
Total income	16		9	29		18
Operating expenses	16		9	29		18
Profit (loss) before income tax	0		0	0		0
Total assets	0		0	0		0
Total loans, net	1,337		2,267	1,337		2,267
Goodwill	0		0	0		0
Total deposits	6,106		8,535	6,106		8,535
WPB | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	194		185	407		354
Other operating income	52		32	104		195
Total operating income (expense)	246		217	511		549
Expected credit losses / provision for credit losses	(8)		(6)	2		(2)
Total income	254		223	509		551
Operating expenses	51		197	226		439
Profit (loss) before income tax	203		26	283		112
Total assets	42,727		43,510	42,727		43,510
Total loans, net	22,654		21,994	22,654		21,994
Goodwill	0		0	0		0
Total deposits	30,085		37,395	30,085		37,395
CMB | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	288		220	573		405
Other operating income	79		73	151		156
Total operating income (expense)	367		293	724		561
Expected credit losses / provision for credit losses	14		54	30		27
Total income	353		239	694		534
Operating expenses	159		143	309		290
Profit (loss) before income tax	194		96	385		244
Total assets	53,983		52,351	53,983		52,351
Total loans, net	23,739		25,454	23,739		25,454
Goodwill	358		358	358		358
Total deposits	45,836		40,170	45,836		40,170
GB | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	123		106	262		184
Other operating income	92		130	146		254
Total operating income (expense)	215		236	408		438
Expected credit losses / provision for credit losses	27		(3)	30		(5)
Total income	188		239	378		443
Operating expenses	141		115	276		232
Profit (loss) before income tax	47		124	102		211
Total assets	9,898		12,385	9,898		12,385
Total loans, net	9,234		11,780	9,234		11,780
Goodwill	0		0	0		0
Total deposits	38,689		41,995	38,689		41,995
MSS | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	15		8	28		17
Other operating income	50		92	146		241
Total operating income (expense)	65		100	174		258
Expected credit losses / provision for credit losses	0		0	0		0
Total income	65		100	174		258
Operating expenses	71		80	140		149
Profit (loss) before income tax	(6)		20	34		109
Total assets	38,003		40,413	38,003		40,413
Total loans, net	215		131	215		131
Goodwill	0		0	0		0
Total deposits	862		1,193	862		1,193
GBM Other | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	(12)		1	(12)		(1)
Other operating income	25		26	46		50
Total operating income (expense)	13		27	34		49
Expected credit losses / provision for credit losses	0		1	0		1
Total income	13		26	34		48
Operating expenses	14		21	32		45
Profit (loss) before income tax	(1)		5	2		3
Total assets	37,603		41,225	37,603		41,225
Total loans, net	305		528	305		528
Goodwill	0		0	0		0
Total deposits	2,633		1,409	2,633		1,409
CC | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	(106)		(20)	(213)		(14)
Other operating income	106		24	197		9
Total operating income (expense)	0		4	(16)		(5)
Expected credit losses / provision for credit losses	0		0	0		0
Total income	0		4	(16)		(5)
Operating expenses	36		115	68		181
Profit (loss) before income tax	(36)		(111)	(84)		(186)
Total assets	3,115		2,314	3,115		2,314
Total loans, net	0		0	0		0
Goodwill	0		0	0		0
Total deposits	$ 0		$ 0	$ 0		$ 0

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at June 30, 2023 and December 31, 2022. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. June 30, 2023December 31, 2022(in millions)AssetsLoans, net$186 $162 Other assets40 44 Total assets$226 $206 LiabilitiesInterest, taxes and other liabilities$35 $22 Total liabilities$35 $22