Loans, Impaired Loans and Allowance for Credit Losses -Summary of Carrying Value of Exposures by Risk Rating (Detail) - CAD ($) $ in Millions		Apr. 30, 2022	Jan. 31, 2022	Oct. 31, 2021
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		$ 694,996	$ 672,830	$ 642,612
Allowance for credit losses		5,294	5,492	5,626
Carrying value of loans net of ACL		689,702	$ 667,338	636,986
Residential mortgages [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		337,714		319,678
Allowance for credit losses		834		802
Carrying value of loans net of ACL		336,880		318,876
Residential mortgages [member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		200,998		192,773
Residential mortgages [member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		79,843		71,074
Residential mortgages [member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		18,181		12,860
Residential mortgages [member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		3,658		3,188
Residential mortgages [member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,254		659
Residential mortgages [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	32,507		37,793
Residential mortgages [member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,273		1,331
Loans to consumers [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		94,437		91,540
Allowance for credit losses		2,171		2,341
Carrying value of loans net of ACL		92,266		89,199
Loans to consumers [member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		30,005		30,253
Loans to consumers [member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		27,131		26,293
Loans to consumers [member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		9,435		9,417
Loans to consumers [member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		8,741		7,993
Loans to consumers [member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,585		1,239
Loans to consumers [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	16,773		15,512
Loans to consumers [member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		767		833
Undrawn loan commitments retail [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments net of ACL		136,287		128,522
Undrawn loan commitments retail [Member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		93,802		88,322
Undrawn loan commitments retail [Member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		20,259		17,892
Undrawn loan commitments retail [Member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		7,767		6,894
Undrawn loan commitments retail [Member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		4,101		3,848
Undrawn loan commitments retail [Member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		362		236
Undrawn loan commitments retail [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL	[1]	9,996		11,330
Total Retail Loans [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		582,060		552,190
Allowance for credit losses		4,112		4,354
Carrying value of loans net of ACL		577,948		547,836
Total Retail Loans [Member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		326,416		312,941
Total Retail Loans [Member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		130,013		117,682
Total Retail Loans [Member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		38,807		32,003
Total Retail Loans [Member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		20,390		18,491
Total Retail Loans [Member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		3,767		2,664
Total Retail Loans [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	60,627		66,245
Total Retail Loans [Member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,040		2,164
Business and government [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		249,223		218,944
Allowance for credit losses		1,182		1,272
Carrying value of loans net of ACL		248,041		217,672
Business and government [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	2,254		2,162
Business and government [member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,224		2,292
Business and government [member] | Investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		134,471		111,678
Business and government [member] | Non investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		107,508		99,515
Business and government [member] | Watch list [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,766		3,297
Undrawn loan commitments business and government [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		270,346		263,546
Allowance for credit losses		49		65
Carrying value of undrawn loan commitments net of ACL		270,297		263,481
Undrawn loan commitments business and government [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL	[1]	4,082		4,155
Undrawn loan commitments business and government [Member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		118		102
Undrawn loan commitments business and government [Member] | Investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		199,375		187,322
Undrawn loan commitments business and government [Member] | Non investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		65,596		69,795
Undrawn loan commitments business and government [Member] | Watch list [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		1,175		2,172
Credit Card [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		13,622		12,450
Allowance for credit losses		1,107		1,211
Carrying value of loans net of ACL		12,515		11,239
Credit Card [member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,611		1,593
Credit Card [member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,780		2,423
Credit Card [member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		3,424		2,832
Credit Card [member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		3,890		3,462
Credit Card [member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		566		530
Credit Card [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	1,351		1,610
Credit Card [member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL				0
Total Non Retail Loans [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		519,569		482,490
Allowance for credit losses		1,231		1,337
Carrying value of loans net of ACL		518,338		481,153
Total Non Retail Loans [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	6,336		6,317
Total Non Retail Loans [Member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,342		2,394
Total Non Retail Loans [Member] | Investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		333,846		299,000
Total Non Retail Loans [Member] | Non investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		173,104		169,310
Total Non Retail Loans [Member] | Watch list [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		3,941		5,469
Stage one exposure [Member] | Residential mortgages [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		327,842		300,681
Allowance for credit losses		168		152
Carrying value of loans net of ACL		327,674		300,529
Stage one exposure [Member] | Residential mortgages [member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		198,894		187,163
Stage one exposure [Member] | Residential mortgages [member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		79,199		69,306
Stage one exposure [Member] | Residential mortgages [member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		17,222		9,170
Stage one exposure [Member] | Residential mortgages [member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,503		904
Stage one exposure [Member] | Residential mortgages [member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		57		16
Stage one exposure [Member] | Residential mortgages [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	29,967		34,122
Stage one exposure [Member] | Loans to consumers [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		87,625		84,021
Allowance for credit losses		655		644
Carrying value of loans net of ACL		86,970		83,377
Stage one exposure [Member] | Loans to consumers [member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		29,855		30,085
Stage one exposure [Member] | Loans to consumers [member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		26,809		25,719
Stage one exposure [Member] | Loans to consumers [member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		8,407		8,290
Stage one exposure [Member] | Loans to consumers [member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		6,937		5,686
Stage one exposure [Member] | Loans to consumers [member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		74		82
Stage one exposure [Member] | Loans to consumers [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	15,543		14,159
Stage one exposure [Member] | Undrawn loan commitments retail [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments net of ACL		134,284		125,299
Stage one exposure [Member] | Undrawn loan commitments retail [Member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		93,791		88,308
Stage one exposure [Member] | Undrawn loan commitments retail [Member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		20,251		17,880
Stage one exposure [Member] | Undrawn loan commitments retail [Member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		7,734		6,858
Stage one exposure [Member] | Undrawn loan commitments retail [Member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		3,785		3,103
Stage one exposure [Member] | Undrawn loan commitments retail [Member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		41		24
Stage one exposure [Member] | Undrawn loan commitments retail [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL	[1]	8,682		9,126
Stage one exposure [Member] | Total Retail Loans [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		561,443		519,888
Allowance for credit losses		1,242		1,148
Carrying value of loans net of ACL		560,201		518,740
Stage one exposure [Member] | Total Retail Loans [Member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		324,099		307,073
Stage one exposure [Member] | Total Retail Loans [Member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		128,931		115,193
Stage one exposure [Member] | Total Retail Loans [Member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		36,720		26,984
Stage one exposure [Member] | Total Retail Loans [Member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		16,312		11,930
Stage one exposure [Member] | Total Retail Loans [Member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		216		143
Stage one exposure [Member] | Total Retail Loans [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	55,165		58,565
Stage one exposure [Member] | Business and government [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		234,079		204,913
Allowance for credit losses		202		186
Carrying value of loans net of ACL		233,877		204,727
Stage one exposure [Member] | Business and government [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	2,243		2,151
Stage one exposure [Member] | Business and government [member] | Investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		133,757		110,786
Stage one exposure [Member] | Business and government [member] | Non investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		98,055		91,945
Stage one exposure [Member] | Business and government [member] | Watch list [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		24		31
Stage one exposure [Member] | Undrawn loan commitments business and government [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		263,437		256,232
Allowance for credit losses		32		26
Carrying value of undrawn loan commitments net of ACL		263,405		256,206
Stage one exposure [Member] | Undrawn loan commitments business and government [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL	[1]	4,082		4,155
Stage one exposure [Member] | Undrawn loan commitments business and government [Member] | Investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		197,941		186,056
Stage one exposure [Member] | Undrawn loan commitments business and government [Member] | Non investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		61,413		66,009
Stage one exposure [Member] | Undrawn loan commitments business and government [Member] | Watch list [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		1		12
Stage one exposure [Member] | Credit Card [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		11,692		9,887
Allowance for credit losses		419		352
Carrying value of loans net of ACL		11,273		9,535
Stage one exposure [Member] | Credit Card [member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,559		1,517
Stage one exposure [Member] | Credit Card [member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,672		2,288
Stage one exposure [Member] | Credit Card [member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		3,357		2,666
Stage one exposure [Member] | Credit Card [member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		3,087		2,237
Stage one exposure [Member] | Credit Card [member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		44		21
Stage one exposure [Member] | Credit Card [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	973		1,158
Stage one exposure [Member] | Total Non Retail Loans [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		497,516		461,145
Allowance for credit losses		234		212
Carrying value of loans net of ACL		497,282		460,933
Stage one exposure [Member] | Total Non Retail Loans [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	6,325		6,306
Stage one exposure [Member] | Total Non Retail Loans [Member] | Investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		331,698		296,842
Stage one exposure [Member] | Total Non Retail Loans [Member] | Non investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		159,468		157,954
Stage one exposure [Member] | Total Non Retail Loans [Member] | Watch list [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		25		43
Stage two exposure [Member] | Residential mortgages [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		8,599		17,666
Allowance for credit losses		273		276
Carrying value of loans net of ACL		8,326		17,390
Stage two exposure [Member] | Residential mortgages [member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,104		5,610
Stage two exposure [Member] | Residential mortgages [member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		644		1,768
Stage two exposure [Member] | Residential mortgages [member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		959		3,690
Stage two exposure [Member] | Residential mortgages [member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,155		2,284
Stage two exposure [Member] | Residential mortgages [member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,197		643
Stage two exposure [Member] | Residential mortgages [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	2,540		3,671
Stage two exposure [Member] | Loans to consumers [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		6,045		6,686
Allowance for credit losses		950		1,071
Carrying value of loans net of ACL		5,095		5,615
Stage two exposure [Member] | Loans to consumers [member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		150		168
Stage two exposure [Member] | Loans to consumers [member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		322		574
Stage two exposure [Member] | Loans to consumers [member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,028		1,127
Stage two exposure [Member] | Loans to consumers [member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,804		2,307
Stage two exposure [Member] | Loans to consumers [member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,511		1,157
Stage two exposure [Member] | Loans to consumers [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	1,230		1,353
Stage two exposure [Member] | Undrawn loan commitments retail [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments net of ACL		2,003		3,223
Stage two exposure [Member] | Undrawn loan commitments retail [Member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		11		14
Stage two exposure [Member] | Undrawn loan commitments retail [Member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		8		12
Stage two exposure [Member] | Undrawn loan commitments retail [Member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		33		36
Stage two exposure [Member] | Undrawn loan commitments retail [Member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		316		745
Stage two exposure [Member] | Undrawn loan commitments retail [Member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		321		212
Stage two exposure [Member] | Undrawn loan commitments retail [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL	[1]	1,314		2,204
Stage two exposure [Member] | Total Retail Loans [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		18,577		30,138
Allowance for credit losses		1,911		2,206
Carrying value of loans net of ACL		16,666		27,932
Stage two exposure [Member] | Total Retail Loans [Member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,317		5,868
Stage two exposure [Member] | Total Retail Loans [Member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,082		2,489
Stage two exposure [Member] | Total Retail Loans [Member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,087		5,019
Stage two exposure [Member] | Total Retail Loans [Member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		4,078		6,561
Stage two exposure [Member] | Total Retail Loans [Member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		3,551		2,521
Stage two exposure [Member] | Total Retail Loans [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	5,462		7,680
Stage two exposure [Member] | Business and government [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		12,920		11,739
Allowance for credit losses		335		431
Carrying value of loans net of ACL		12,585		11,308
Stage two exposure [Member] | Business and government [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	11		11
Stage two exposure [Member] | Business and government [member] | Investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		714		892
Stage two exposure [Member] | Business and government [member] | Non investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		9,453		7,570
Stage two exposure [Member] | Business and government [member] | Watch list [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,742		3,266
Stage two exposure [Member] | Undrawn loan commitments business and government [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		6,791		7,212
Allowance for credit losses		17		39
Carrying value of undrawn loan commitments net of ACL		6,774		7,173
Stage two exposure [Member] | Undrawn loan commitments business and government [Member] | Investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		1,434		1,266
Stage two exposure [Member] | Undrawn loan commitments business and government [Member] | Non investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		4,183		3,786
Stage two exposure [Member] | Undrawn loan commitments business and government [Member] | Watch list [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL		1,174		2,160
Stage two exposure [Member] | Credit Card [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		1,930		2,563
Allowance for credit losses		688		859
Carrying value of loans net of ACL		1,242		1,704
Stage two exposure [Member] | Credit Card [member] | Very low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		52		76
Stage two exposure [Member] | Credit Card [member] | Low probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		108		135
Stage two exposure [Member] | Credit Card [member] | Medium probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		67		166
Stage two exposure [Member] | Credit Card [member] | High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		803		1,225
Stage two exposure [Member] | Credit Card [member] | Very High probability of default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		522		509
Stage two exposure [Member] | Credit Card [member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	378		452
Stage two exposure [Member] | Total Non Retail Loans [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		19,711		18,951
Allowance for credit losses		352		470
Carrying value of loans net of ACL		19,359		18,481
Stage two exposure [Member] | Total Non Retail Loans [Member] | Loans not graded [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[1]	11		11
Stage two exposure [Member] | Total Non Retail Loans [Member] | Investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		2,148		2,158
Stage two exposure [Member] | Total Non Retail Loans [Member] | Non investment grade [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		13,636		11,356
Stage two exposure [Member] | Total Non Retail Loans [Member] | Watch list [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL		3,916		5,426
Stage three exposure [Member] | Residential mortgages [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[2]	1,273		1,331
Allowance for credit losses	[2]	393		374
Carrying value of loans net of ACL	[2]	880		957
Stage three exposure [Member] | Residential mortgages [member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[2]	1,273		1,331
Stage three exposure [Member] | Loans to consumers [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[2]	767		833
Allowance for credit losses	[2]	566		626
Carrying value of loans net of ACL	[2]	201		207
Stage three exposure [Member] | Loans to consumers [member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[2]	767		833
Stage three exposure [Member] | Total Retail Loans [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[2]	2,040		2,164
Allowance for credit losses	[2]	959		1,000
Carrying value of loans net of ACL	[2]	1,081		1,164
Stage three exposure [Member] | Total Retail Loans [Member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[2]	2,040		2,164
Stage three exposure [Member] | Business and government [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[2]	2,224		2,292
Allowance for credit losses	[2]	645		655
Carrying value of loans net of ACL	[2]	1,579		1,637
Stage three exposure [Member] | Business and government [member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[2]	2,224		2,292
Stage three exposure [Member] | Undrawn loan commitments business and government [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL	[2]	118		102
Carrying value of undrawn loan commitments net of ACL	[2]	118		102
Stage three exposure [Member] | Undrawn loan commitments business and government [Member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of undrawn loan commitments before ACL	[2]	118		102
Stage three exposure [Member] | Total Non Retail Loans [Member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[2]	2,342		2,394
Allowance for credit losses	[2]	645		655
Carrying value of loans net of ACL	[2]	1,697		1,739
Stage three exposure [Member] | Total Non Retail Loans [Member] | Default [member]
Disclosure of detailed information about financial instruments [line items]
Carrying value of loans before ACL	[2]	$ 2,342		$ 2,394

[1] Portfolios where the customer account level ‘Probability of Default’ has not been determined have been included in the ‘Loans not graded’ category.

[2] Stage 3 includes purchased or originated credit-impaired loans.