Business Segments - Summary on Reconciliation of Results Under IFRS to US GAAP (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024		Mar. 31, 2023	Dec. 31, 2023	[1]
Operating Statistics [Line Items]
Net interest income (expense)	$ 426		$ 483
Other operating income (expense)	539		453
Total operating income (expense)	965		936
Provision for credit losses	2		20
Total income	963		916
Operating expenses	685		629
Income before income tax	278		287
Total assets	166,966	[1]	166,550	$ 168,238
Total loans, net	59,216	[1]	58,874	58,396
Goodwill	458	[1]	458	458
Total deposits	122,053	[1]	122,168	$ 121,283
Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	447		543
Other operating income	505		386
Total operating income	952		929
Expected credit losses / provision for credit losses	(7)		29
Total income	959		900
Operating expenses	673		579
Profit (loss) before income tax	286		321
Total assets	181,561		182,365
Total loans, net	57,992		57,814
Goodwill	358		358
Total deposits	114,283		117,455
Net interest income (expense)			543
Group Reporting Basis Adjustments
Operating Statistics [Line Items]
Net interest income (expense)	7		1
Other operating income	(3)		(7)
Total operating income	4		(6)
Expected credit losses / provision for credit losses	9		(9)
Total income	(5)		3
Operating expenses	3		37
Profit (loss) before income tax	(8)		(34)
Total assets	(14,595)		(15,815)
Total loans, net	(561)		(747)
Goodwill	100		100
Total deposits	(1,750)		(2,022)
Group Reporting Basis Reclassifications
Operating Statistics [Line Items]
Net interest income (expense)	(28)		(61)
Other operating income	37		74
Total operating income	9		13
Expected credit losses / provision for credit losses	0		0
Total income	9		13
Operating expenses	9		13
Profit (loss) before income tax	0		0
Total assets	0		0
Total loans, net	1,785		1,807
Goodwill	0		0
Total deposits	9,520		6,735
WPB | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	179		213
Other operating income	67		52
Total operating income	246		265
Expected credit losses / provision for credit losses	0		10
Total income	246		255
Operating expenses	187		175
Profit (loss) before income tax	59		80
Total assets	37,255		42,518
Total loans, net	23,955		22,429
Goodwill	0		0
Total deposits	29,936		31,166
CMB | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	292		285
Other operating income	78		72
Total operating income	370		357
Expected credit losses / provision for credit losses	(2)		16
Total income	372		341
Operating expenses	179		150
Profit (loss) before income tax	193		191
Total assets	56,195		54,607
Total loans, net	23,880		24,793
Goodwill	358		358
Total deposits	40,214		43,229
GB | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	117		139
Other operating income	84		54
Total operating income	201		193
Expected credit losses / provision for credit losses	(5)		3
Total income	206		190
Operating expenses	131		135
Profit (loss) before income tax	75		55
Total assets	10,165		10,506
Total loans, net	9,717		9,812
Goodwill	0		0
Total deposits	41,137		40,422
MSS | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	9		13
Other operating income	81		96
Total operating income	90		109
Expected credit losses / provision for credit losses	0		0
Total income	90		109
Operating expenses	79		69
Profit (loss) before income tax	11		40
Total assets	33,767		34,692
Total loans, net	73		507
Goodwill	0		0
Total deposits	1,157		1,260
Net interest income (expense)			13
GBM Other | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	18		0
Other operating income	22		21
Total operating income	40		21
Expected credit losses / provision for credit losses	0		0
Total income	40		21
Operating expenses	22		18
Profit (loss) before income tax	18		3
Total assets	40,290		37,546
Total loans, net	367		273
Goodwill	0		0
Total deposits	1,839		1,378
CC | Operating Segments
Operating Statistics [Line Items]
Net interest income (expense)	(168)		(107)
Other operating income	173		91
Total operating income	5		(16)
Expected credit losses / provision for credit losses	0		0
Total income	5		(16)
Operating expenses	75		32
Profit (loss) before income tax	(70)		(48)
Total assets	3,889		2,496
Total loans, net	0		0
Goodwill	0		0
Total deposits	$ 0		0
Net interest income (expense)			$ (107)

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at March 31, 2024 and December 31, 2023. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 15, "Variable Interest Entities," for additional information. March 31, 2024December 31, 2023(in millions)AssetsOther assets$21 $23 Total assets$21 $23 LiabilitiesInterest, taxes and other liabilities$28 $17 Total liabilities$28 $17