v3.26.1
Loans, Impaired Loans and Allowance for Credit Losses -Summary of Carrying Value of Exposures by Risk Rating (Detail) - CAD ($)
$ in Millions
Jul. 31, 2026
Apr. 30, 2026
Oct. 31, 2025
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL $ 777,884 $ 764,584 $ 778,508
Allowance for credit losses 7,329 7,150 7,463
Carrying value of loans net of ACL 770,555 $ 757,434 771,045
Residential mortgages [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 366,643   370,191
Allowance for credit losses 1,495   1,460
Carrying value of loans net of ACL 365,148   368,731
Residential mortgages [member] | Very low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 223,317   223,888
Residential mortgages [member] | Low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 89,361   88,575
Residential mortgages [member] | Medium probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 25,917   24,488
Residential mortgages [member] | High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 8,244   9,009
Residential mortgages [member] | Very High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 2,948   3,218
Residential mortgages [member] | Loans not graded [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [1] 13,798   18,110
Residential mortgages [member] | Default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 3,058   2,903
Personal loans [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 108,016   110,567
Allowance for credit losses 2,272   2,432
Carrying value of loans net of ACL 105,744   108,135
Personal loans [member] | Very low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 31,624   31,211
Personal loans [member] | Low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 22,003   21,826
Personal loans [member] | Medium probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 13,075   12,964
Personal loans [member] | High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 14,163   15,990
Personal loans [member] | Very High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 2,208   2,686
Personal loans [member] | Loans not graded [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [1] 23,998   24,819
Personal loans [member] | Default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 945   1,071
Credit Card [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 16,365   18,045
Allowance for credit losses 1,157   1,355
Carrying value of loans net of ACL 15,208   16,690
Credit Card [member] | Very low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 2,688   2,648
Credit Card [member] | Low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 2,822   3,182
Credit Card [member] | Medium probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 4,306   4,818
Credit Card [member] | High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 4,127   5,152
Credit Card [member] | Very High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 1,178   1,224
Credit Card [member] | Loans not graded [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [1] 1,244   1,021
Credit Card [member] | Default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 0    
Undrawn loan commitments retail [Member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of undrawn loan commitments net of ACL 178,632   174,822
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 134,979   126,936
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 22,087   22,173
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 7,073   9,582
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 2,545   4,678
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 262   365
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] 11,686   11,088
Total retail loans [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 669,656   673,625
Allowance for credit losses 4,924   5,247
Carrying value of loans net of ACL 664,732   668,378
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 392,608   384,683
Total retail loans [member] | Low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 136,273   135,756
Total retail loans [member] | Medium probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 50,371   51,852
Total retail loans [member] | High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 29,079   34,829
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 6,596   7,493
Total retail loans [member] | Loans not graded [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [1] 50,726   55,038
Total retail loans [member] | Default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 4,003   3,974
Business and government [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 286,860   279,705
Allowance for credit losses 2,405   2,216
Carrying value of loans net of ACL 284,455   277,489
Business and government [member] | Loans not graded [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [1] 2,742   2,521
Business and government [member] | Default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 3,798   3,270
Business and government [member] | Investment grade [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 149,608   140,271
Business and government [member] | Non investment grade [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 126,423   129,168
Business and government [member] | Watch list [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 4,289   4,475
Undrawn loan commitments business and government [Member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of undrawn loan commitments before ACL 334,513   311,347
Carrying value of undrawn loan commitments net of ACL 334,311   311,172
Allowance for credit losses 202   175
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] 4,582   4,594
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 73   31
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 266,217   243,738
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 62,853   61,977
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 788   1,007
Total Non Retail Loans [Member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 621,373   591,052
Allowance for credit losses 2,607   2,391
Carrying value of loans net of ACL 618,766   588,661
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] 7,324   7,115
Total Non Retail Loans [Member] | Default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 3,871   3,301
Total Non Retail Loans [Member] | Investment grade [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 415,825   384,009
Total Non Retail Loans [Member] | Non investment grade [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 189,276   191,145
Total Non Retail Loans [Member] | Watch list [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 5,077   5,482
Stage one exposure [Member] | Residential mortgages [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 337,767   339,517
Allowance for credit losses 209   196
Carrying value of loans net of ACL 337,558   339,321
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 220,338   219,905
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 85,951   83,755
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 15,788   15,870
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 2,400   3,002
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 7   48
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] 13,283   16,937
Stage one exposure [Member] | Personal loans [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 96,629   97,801
Allowance for credit losses 578   613
Carrying value of loans net of ACL 96,051   97,188
Stage one exposure [Member] | Personal loans [member] | Very low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 31,474   31,009
Stage one exposure [Member] | Personal loans [member] | Low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 21,269   21,075
Stage one exposure [Member] | Personal loans [member] | Medium probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 13,037   12,886
Stage one exposure [Member] | Personal loans [member] | High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 8,797   10,331
Stage one exposure [Member] | Personal loans [member] | Very High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 45   35
Stage one exposure [Member] | Personal loans [member] | Loans not graded [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [1] 22,007   22,465
Stage one exposure [Member] | Credit Card [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 12,951   14,421
Allowance for credit losses 263   338
Carrying value of loans net of ACL 12,688   14,083
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 2,687   2,646
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 2,819   3,171
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 4,289   4,792
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 2,325   3,210
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 12   20
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] 819   582
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 175,528   171,452
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 134,786   126,681
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 22,045   22,102
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 7,066   9,569
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 2,177   4,047
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 3   14
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] 9,451   9,039
Stage one exposure [Member] | Total retail loans [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 622,875   623,191
Allowance for credit losses 1,050   1,147
Carrying value of loans net of ACL 621,825   622,044
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 389,285   380,241
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 132,084   130,103
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 40,180   43,117
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 15,699   20,590
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 67   117
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] 45,560   49,023
Stage one exposure [Member] | Business and government [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 271,836   263,280
Allowance for credit losses 733   713
Carrying value of loans net of ACL 271,103   262,567
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] 2,717   2,485
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 148,716   138,789
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 120,397   121,999
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 6   7
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 331,030   307,366
Carrying value of undrawn loan commitments net of ACL 330,880   307,225
Allowance for credit losses 150   141
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] 4,581   4,593
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 265,216   242,637
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 61,233   60,136
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 0    
Stage one exposure [Member] | Total Non Retail Loans [Member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 602,866   570,646
Allowance for credit losses 883   854
Carrying value of loans net of ACL 601,983   569,792
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] 7,298   7,078
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 413,932   381,426
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 181,630   182,135
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 6   7
Stage two exposure [Member] | Residential mortgages [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 25,818   27,771
Allowance for credit losses 436   424
Carrying value of loans net of ACL 25,382   27,347
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 2,979   3,983
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 3,410   4,820
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 10,129   8,618
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 5,844   6,007
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 2,941   3,170
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] 515   1,173
Stage two exposure [Member] | Personal loans [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 10,442   11,695
Allowance for credit losses 1,138   1,215
Carrying value of loans net of ACL 9,304   10,480
Stage two exposure [Member] | Personal loans [member] | Very low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 150   202
Stage two exposure [Member] | Personal loans [member] | Low probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 734   751
Stage two exposure [Member] | Personal loans [member] | Medium probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 38   78
Stage two exposure [Member] | Personal loans [member] | High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 5,366   5,659
Stage two exposure [Member] | Personal loans [member] | Very High probability of default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 2,163   2,651
Stage two exposure [Member] | Personal loans [member] | Loans not graded [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [1] 1,991   2,354
Stage two exposure [Member] | Credit Card [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 3,414   3,624
Allowance for credit losses 894   1,017
Carrying value of loans net of ACL 2,520   2,607
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 1   2
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 3   11
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 17   26
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 1,802   1,942
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 1,166   1,204
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] 425   439
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 3,104   3,370
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 193   255
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 42   71
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 7   13
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 368   631
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 259   351
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] 2,235   2,049
Stage two exposure [Member] | Total retail loans [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 42,778   46,460
Allowance for credit losses 2,468   2,656
Carrying value of loans net of ACL 40,310   43,804
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 3,323   4,442
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 4,189   5,653
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 10,191   8,735
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 13,380   14,239
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 6,529   7,376
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] 5,166   6,015
Stage two exposure [Member] | Business and government [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 11,226   13,155
Allowance for credit losses 580   606
Carrying value of loans net of ACL 10,646   12,549
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] 25   36
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 892   1,482
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 6,026   7,169
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 4,283   4,468
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 3,410   3,950
Carrying value of undrawn loan commitments net of ACL 3,371   3,916
Allowance for credit losses 39   34
Stage two 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] 1   1
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 1,001   1,101
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 1,620   1,841
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 788   1,007
Stage two exposure [Member] | Total Non Retail Loans [Member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL 14,636   17,105
Allowance for credit losses 619   640
Carrying value of loans net of ACL 14,017   16,465
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] 26   37
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 1,893   2,583
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 7,646   9,010
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 5,071   5,475
Stage three exposure [Member] | Residential mortgages [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [2] 3,058   2,903
Allowance for credit losses [2] 850   840
Carrying value of loans net of ACL [2] 2,208   2,063
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] 3,058   2,903
Stage three exposure [Member] | Personal loans [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [2] 945   1,071
Allowance for credit losses [2] 556   604
Carrying value of loans net of ACL [2] 389   467
Stage three exposure [Member] | Personal loans [member] | Default [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [2] 945   1,071
Stage three exposure [Member] | Total retail loans [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [2] 4,003   3,974
Allowance for credit losses [2] 1,406   1,444
Carrying value of loans net of ACL [2] 2,597   2,530
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] 4,003   3,974
Stage three exposure [Member] | Business and government [member]      
Disclosure of detailed information about financial instruments [line items]      
Carrying value of loans before ACL [2] 3,798   3,270
Allowance for credit losses [2] 1,092   897
Carrying value of loans net of ACL [2] 2,706   2,373
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] 3,798   3,270
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] 73   31
Carrying value of undrawn loan commitments net of ACL [2] 60   31
Allowance for credit losses [2] 13    
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] 73   31
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] 3,871   3,301
Allowance for credit losses [2] 1,105   897
Carrying value of loans net of ACL [2] 2,766   2,404
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] $ 3,871   $ 3,301
[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.