Business Segments - Summary on Reconciliation of Results Under Ifrs to Us Gaap (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Dec. 31, 2013
Operating Statistics [Line Items]
Net interest income	$ 543	[1]	$ 492	[1]	$ 1,735	[1]	$ 1,515	[1]
Other operating income	386		432		1,147		1,590
Total operating income	929		924		2,882		3,105
Loan impairment charges	23	[2]	54	[2]	124	[2]	142	[2]
Revenues	906		870		2,758		2,963
Operating expenses	934	[3]	834	[3]	2,560	[3]	2,368	[3]
Income (loss) before income tax	(28)		36		198		595
Total assets	175,012	[4]	187,375		175,012	[4]	187,375		185,487	[4]
Total loans, net	72,808		67,115		72,808		67,115		67,089
Goodwill	1,612		2,228		1,612		2,228		1,612
Total deposits	108,677		112,921		108,677		112,921		112,608
Segment Reconciling Items [Member]
Operating Statistics [Line Items]
Net interest income	8	[1]	(2)	[1]	(1)	[1]	(9)	[1]
Other operating income	(8)		2		1		9
Total operating income	0		0		0		0
Loan impairment charges	0	[2]	0	[2]	0	[2]	0	[2]
Revenues	0		0		0		0
Operating expenses	0	[3]	0	[3]	0	[3]	0	[3]
Income (loss) before income tax	0		0		0		0
Total assets	0		0		0		0
Total loans, net	0		0		0		0
Goodwill	0		0		0		0
Total deposits	0		0		0		0
Aggregate [Member]
Operating Statistics [Line Items]
Net interest income	527	[1]	502	[1]	1,693	[1]	1,558	[1]
Other operating income	422		445		1,262		1,569
Total operating income	949		947		2,955		3,127
Loan impairment charges	47	[2]	70	[2]	210	[2]	148	[2]
Revenues	902		877		2,745		2,979
Operating expenses	1,153	[3]	818	[3]	2,709	[3]	2,392	[3]
Income (loss) before income tax	(251)		59		36		587
Total assets	225,303		240,842		225,303		240,842
Total loans, net	69,154		63,025		69,154		63,025
Goodwill	1,264		1,744		1,264		1,744
Total deposits	95,105		98,389		95,105		98,389
Ifrs Adjustments [Member]
Operating Statistics [Line Items]
Net interest income	(20)	[1],[5]	(17)	[1],[5]	(51)	[1],[5]	(55)	[1],[5]
Other operating income	7	[5]	(8)	[5]	(3)	[5]	30	[5]
Total operating income	(13)	[5]	(25)	[5]	(54)	[5]	(25)	[5]
Loan impairment charges	(14)	[2],[5]	(11)	[2],[5]	(62)	[2],[5]	(15)	[2],[5]
Revenues	1	[5]	(14)	[5]	8	[5]	(10)	[5]
Operating expenses	(222)	[3],[5]	9	[3],[5]	(154)	[3],[5]	(18)	[3],[5]
Income (loss) before income tax	223	[5]	(23)	[5]	162	[5]	8	[5]
Total assets	(50,353)	[5]	(53,563)	[5]	(50,353)	[5]	(53,563)	[5]
Total loans, net	1,224	[5]	1,794	[5]	1,224	[5]	1,794	[5]
Goodwill	348	[5]	484	[5]	348	[5]	484	[5]
Total deposits	(3,758)	[5]	(4,491)	[5]	(3,758)	[5]	(4,491)	[5]
Ifrs Reclassifications [Member]
Operating Statistics [Line Items]
Net interest income	36	[1],[6]	7	[1],[6]	93	[1],[6]	12	[1],[6]
Other operating income	(43)	[6]	(5)	[6]	(112)	[6]	(9)	[6]
Total operating income	(7)	[6]	2	[6]	(19)	[6]	3	[6]
Loan impairment charges	(10)	[2],[6]	(5)	[2],[6]	(24)	[2],[6]	9	[2],[6]
Revenues	3	[6]	7	[6]	5	[6]	(6)	[6]
Operating expenses	3	[3],[6]	7	[3],[6]	5	[3],[6]	(6)	[3],[6]
Income (loss) before income tax	0	[6]	0	[6]	0	[6]	0	[6]
Total assets	62	[6]	96	[6]	62	[6]	96	[6]
Total loans, net	2,430	[6]	2,296	[6]	2,430	[6]	2,296	[6]
Goodwill		[6]	0	[6]		[6]	0	[6]
Total deposits	17,330	[6]	19,023	[6]	17,330	[6]	19,023	[6]
RBWM [Member] | Operating Segments [Member]
Operating Statistics [Line Items]
Net interest income	196	[1]	205	[1]	606	[1]	626	[1]
Other operating income	98		81		315		270
Total operating income	294		286		921		896
Loan impairment charges	11	[2]	44	[2]	34	[2]	97	[2]
Revenues	283		242		887		799
Operating expenses	343	[3]	301	[3]	920	[3]	892	[3]
Income (loss) before income tax	(60)		(59)		(33)		(93)
Total assets	19,339		19,297		19,339		19,297
Total loans, net	16,491		16,221		16,491		16,221
Goodwill	581		581		581		581
Total deposits	28,515		30,594		28,515		30,594
CMB [Member] | Operating Segments [Member]
Operating Statistics [Line Items]
Net interest income	204	[1]	181	[1]	593	[1]	523	[1]
Other operating income	90		77		222		219
Total operating income	294		258		815		742
Loan impairment charges	29	[2]	26	[2]	119	[2]	41	[2]
Revenues	265		232		696		701
Operating expenses	169	[3]	169	[3]	501	[3]	502	[3]
Income (loss) before income tax	96		63		195		199
Total assets	27,769		22,571		27,769		22,571
Total loans, net	26,626		21,414		26,626		21,414
Goodwill	358		358		358		358
Total deposits	22,616		21,614		22,616		21,614
GBM [Member] | Operating Segments [Member]
Operating Statistics [Line Items]
Net interest income	74	[1]	78	[1]	280	[1]	312	[1]
Other operating income	191		296		636		973
Total operating income	265		374		916		1,285
Loan impairment charges	11	[2]	(3)	[2]	66	[2]	6	[2]
Revenues	254		377		850		1,279
Operating expenses	553	[3]	255	[3]	1,031	[3]	735	[3]
Income (loss) before income tax	(299)		122		(181)		544
Total assets	169,686		190,174		169,686		190,174
Total loans, net	20,056		19,521		20,056		19,521
Goodwill	0		480		0		480
Total deposits	32,753		34,306		32,753		34,306
PB [Member] | Operating Segments [Member]
Operating Statistics [Line Items]
Net interest income	47	[1]	46	[1]	152	[1]	140	[1]
Other operating income	28		27		78		85
Total operating income	75		73		230		225
Loan impairment charges	(4)	[2]	3	[2]	(9)	[2]	4	[2]
Revenues	79		70		239		221
Operating expenses	58	[3]	62	[3]	174	[3]	189	[3]
Income (loss) before income tax	21		8		65		32
Total assets	7,670		7,996		7,670		7,996
Total loans, net	5,981		5,869		5,981		5,869
Goodwill	325		325		325		325
Total deposits	11,221		11,875		11,221		11,875
Other [Member] | Operating Segments [Member]
Operating Statistics [Line Items]
Net interest income	(2)	[1]	(6)	[1]	63	[1]	(34)	[1]
Other operating income	23		(38)		10		13
Total operating income	21		(44)		73		(21)
Loan impairment charges	0	[2]	0	[2]	0	[2]	0	[2]
Revenues	21		(44)		73		(21)
Operating expenses	30	[3]	31	[3]	83	[3]	74	[3]
Income (loss) before income tax	(9)		(75)		(10)		(95)
Total assets	839		804		839		804
Total loans, net	0		0		0		0
Goodwill	0		0		0		0
Total deposits	$ 0		$ 0		$ 0		$ 0

[1] Net interest income of each segment represents the difference between actual interest earned on assets and interest paid on liabilities of the segment adjusted for a funding charge or credit. Segments are charged a cost to fund assets (e.g. customer loans) and receive a funding credit for funds provided (e.g. customer deposits) based on equivalent market rates. The objective of these charges/credits is to transfer interest rate risk from the segments to one centralized unit in Balance Sheet Management and more appropriately reflect the profitability of segments.

[2] The provision assigned to the segments is based on the segments' net charge offs and the change in allowance for credit losses.

[3] Expenses for the segments include fully apportioned corporate overhead expenses.

[4] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") as of September 30, 2014 and December 31, 2013 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 16, "Variable Interest Entities," for additional information. Assets: Interest bearing deposits with banks, $3 million and $5 million, Securities held-to-maturity, $76 million and $200 million Other assets $436 million and $502 million. Total assets $515 million and $707 million respectively. Liabilities: Long-term debt $92 million and $92 million, Interest, taxes and other liabilities $81 million and $93 million. Total liabilities $173 million and $185 million, respectively.

[5] Represents adjustments associated with differences between IFRSs and U.S. GAAP bases of accounting.

[6] Represents differences in financial statement presentation between IFRSs and U.S. GAAP.