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Derivative Instruments - Schedule of Notional Amounts of Trading Derivatives (Detail) - CAD ($) $ in Millions | Oct. 31, 2025 | Oct. 31, 2024
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Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | $ 21,343,075 | $ 25,192,367
Foreign exchange contracts [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 2,541,417 | 1,855,607
Foreign exchange contracts [member] | Swap contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 1,371,507 | 1,002,323
Foreign exchange contracts [member] | Futures contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 10,864 | 1,751
Foreign exchange contracts [member] | Forward contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 940,640 | 679,927
Commodity contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 123,350 | 155,533
Commodity contract [member] | Swap contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 22,128 | 20,328
Commodity contract [member] | Futures contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 38,470 | 36,071
Credit Contracts [Member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 55,267 | 39,561
Trading Derivatives [Member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 20,787,616 | 24,687,630
Trading Derivatives [Member] | Equity contracts [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 443,980 | 471,160
Trading Derivatives [Member] | Interest rate swap contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 17,696,549 | 22,213,397
Trading Derivatives [Member] | Interest rate swap contract [member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 499,447 | 390,490
Trading Derivatives [Member] | Interest rate swap contract [member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 439,387 | 282,189
Trading Derivatives [Member] | Interest rate swap contract [member] | Swap contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 14,178,539 | 16,390,827
Trading Derivatives [Member] | Interest rate swap contract [member] | Forward rate agreements [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 841,547 | 3,414,449
Trading Derivatives [Member] | Interest rate swap contract [member] | Futures contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 1,737,629 | 1,735,442
Trading Derivatives [Member] | Foreign exchange contracts [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 2,468,470 | 1,807,979
Trading Derivatives [Member] | Foreign exchange contracts [member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 105,191 | 80,148
Trading Derivatives [Member] | Foreign exchange contracts [member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 113,215 | 91,458
Trading Derivatives [Member] | Foreign exchange contracts [member] | Futures contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 10,864 | 1,751
Trading Derivatives [Member] | Foreign exchange contracts [member] | Cross currency swaps [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 63,306 | 64,100
Trading Derivatives [Member] | Foreign exchange contracts [member] | Cross currency interest rate contracts [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 1,235,923 | 891,272
Trading Derivatives [Member] | Foreign exchange contracts [member] | Forward contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 939,971 | 679,250
Trading Derivatives [Member] | Commodity contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 123,350 | 155,533
Trading Derivatives [Member] | Commodity contract [member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 31,832 | 49,426
Trading Derivatives [Member] | Commodity contract [member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 30,920 | 49,708
Trading Derivatives [Member] | Commodity contract [member] | Swap contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 22,128 | 20,328
Trading Derivatives [Member] | Commodity contract [member] | Futures contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 38,470 | 36,071
Trading Derivatives [Member] | Credit Contracts [Member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 55,267 | 39,561
Trading Derivatives [Member] | Credit Contracts [Member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 31,760 | 23,350
Trading Derivatives [Member] | Credit Contracts [Member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 23,507 | 16,211
Trading Derivatives [Member] | Exchange Traded [Member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 2,292,517 | 2,365,845
Trading Derivatives [Member] | Exchange Traded [Member] | Equity contracts [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 256,701 | 333,126
Trading Derivatives [Member] | Exchange Traded [Member] | Interest rate swap contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 1,922,081 | 1,898,706
Trading Derivatives [Member] | Exchange Traded [Member] | Interest rate swap contract [member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 130,231 | 136,796
Trading Derivatives [Member] | Exchange Traded [Member] | Interest rate swap contract [member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 54,221 | 26,468
Trading Derivatives [Member] | Exchange Traded [Member] | Interest rate swap contract [member] | Futures contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 1,737,629 | 1,735,442
Trading Derivatives [Member] | Exchange Traded [Member] | Foreign exchange contracts [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 23,309 | 8,571
Trading Derivatives [Member] | Exchange Traded [Member] | Foreign exchange contracts [member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 6,800 | 3,572
Trading Derivatives [Member] | Exchange Traded [Member] | Foreign exchange contracts [member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 5,645 | 3,248
Trading Derivatives [Member] | Exchange Traded [Member] | Foreign exchange contracts [member] | Futures contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 10,864 | 1,751
Trading Derivatives [Member] | Exchange Traded [Member] | Commodity contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 90,426 | 125,442
Trading Derivatives [Member] | Exchange Traded [Member] | Commodity contract [member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 25,126 | 43,931
Trading Derivatives [Member] | Exchange Traded [Member] | Commodity contract [member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 26,830 | 45,440
Trading Derivatives [Member] | Exchange Traded [Member] | Commodity contract [member] | Futures contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 38,470 | 36,071
Trading Derivatives [Member] | Over the Counter [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 18,495,099 | 22,321,785
Trading Derivatives [Member] | Over the Counter [member] | Equity contracts [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 187,279 | 138,034
Trading Derivatives [Member] | Over the Counter [member] | Interest rate swap contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 15,774,468 | 20,314,691
Trading Derivatives [Member] | Over the Counter [member] | Interest rate swap contract [member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 369,216 | 253,694
Trading Derivatives [Member] | Over the Counter [member] | Interest rate swap contract [member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 385,166 | 255,721
Trading Derivatives [Member] | Over the Counter [member] | Interest rate swap contract [member] | Swap contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 14,178,539 | 16,390,827
Trading Derivatives [Member] | Over the Counter [member] | Interest rate swap contract [member] | Forward rate agreements [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 841,547 | 3,414,449
Trading Derivatives [Member] | Over the Counter [member] | Foreign exchange contracts [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 2,445,161 | 1,799,408
Trading Derivatives [Member] | Over the Counter [member] | Foreign exchange contracts [member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 98,391 | 76,576
Trading Derivatives [Member] | Over the Counter [member] | Foreign exchange contracts [member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 107,570 | 88,210
Trading Derivatives [Member] | Over the Counter [member] | Foreign exchange contracts [member] | Cross currency swaps [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 63,306 | 64,100
Trading Derivatives [Member] | Over the Counter [member] | Foreign exchange contracts [member] | Cross currency interest rate contracts [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 1,235,923 | 891,272
Trading Derivatives [Member] | Over the Counter [member] | Foreign exchange contracts [member] | Forward contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount | [1] | 939,971 | 679,250
Trading Derivatives [Member] | Over the Counter [member] | Commodity contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 32,924 | 30,091
Trading Derivatives [Member] | Over the Counter [member] | Commodity contract [member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 6,706 | 5,495
Trading Derivatives [Member] | Over the Counter [member] | Commodity contract [member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 4,090 | 4,268
Trading Derivatives [Member] | Over the Counter [member] | Commodity contract [member] | Swap contract [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 22,128 | 20,328
Trading Derivatives [Member] | Over the Counter [member] | Credit Contracts [Member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 55,267 | 39,561
Trading Derivatives [Member] | Over the Counter [member] | Credit Contracts [Member] | Purchased options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | 31,760 | 23,350
Trading Derivatives [Member] | Over the Counter [member] | Credit Contracts [Member] | Written options [member] |  |  |
Disclosure Of Derivative Financial Instruments [Line Items] |  |  |
Notional amount |  | $ 23,507 | $ 16,211
[1] | Gold contracts are included in foreign exchange contracts.

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