Investments in Equity-Accounted Associates and Joint Ventures - Additional Information (Detail) - CAD ($)	12 Months Ended
Oct. 31, 2020	Oct. 31, 2019
Disclosure Of Joint Ventures And Associates [Line Items]
Cumulative unrecognised share of losses of joint ventures	$ 0
Unrecognised share of losses of joint ventures	0
Investments in associates	71,000,000	$ 57,000,000
Unrecognized share of losses of associate	0
Cumulative unrecognized share of losses of associate	0
Top of range [member]
Disclosure Of Joint Ventures And Associates [Line Items]
Investment commitment in associates	0	0
Listed associates [Member] \| At Carrying Value [Member]
Disclosure Of Joint Ventures And Associates [Line Items]
Investments in associates	10,000,000	9,000,000
Listed associates [Member] \| At fair value [member]
Disclosure Of Joint Ventures And Associates [Line Items]
Investments in associates, fair value where price quotations published	10,000,000	9,000,000
Unlisted Associates [member] \| At Carrying Value [Member]
Disclosure Of Joint Ventures And Associates [Line Items]
Investments in associates	61,000,000	48,000,000
Unlisted Associates [member] \| At fair value [member]
Disclosure Of Joint Ventures And Associates [Line Items]
Investments in associates, fair value where price quotations not published	83,000,000	76,000,000
Associates [member]
Disclosure Of Joint Ventures And Associates [Line Items]
Undrawn credit commitments	79,000,000	79,000,000
Loans	$ 0	0
Joint ventures [member]
Disclosure Of Joint Ventures And Associates [Line Items]
Description of joint venture	CIBC is a 50/50 joint venture partner with The Bank of New York Mellon in two joint ventures CIBC Mellon Trust Company and CIBC Mellon Global Securities Services Company
Country of incorporation of joint venture	Canada
Proportion of ownership interest in joint venture	50.00%
Loans	$ 0	0
Undrawn credit commitments	164,000,000	128,000,000
Corporate and Other [member]
Disclosure Of Joint Ventures And Associates [Line Items]
Investment in joint venture	587,000,000	529,000,000
Investments in associates	24,000,000	19,000,000
Canadian Personal and Business Banking [member]
Disclosure Of Joint Ventures And Associates [Line Items]
Investments in associates	10,000,000	5,000,000
Capital Markets [member]
Disclosure Of Joint Ventures And Associates [Line Items]
Investments in associates	$ 37,000,000	$ 33,000,000

Disclosure Of Joint Ventures And Associates [Line Items]

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Fair value of investments in associates where price quotations are not published.

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Investment commitment in associates.

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The amount of loans the entity has made to its associates.

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Loans to joint ventures.

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Undrawn credit commitments to associates.

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Undrawn credit commitments to joint ventures.

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The country in which a joint venture of the entity is incorporated. [Refer: Joint ventures [member]]

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The cumulative amount of the unrecognised share of losses of associates if the entity has stopped recognising its share of losses when applying the equity method. [Refer: Associates [member]; Unrecognised share of losses of associates]

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The cumulative amount of the unrecognised share of losses of joint ventures if the entity has stopped recognising its share of losses when applying the equity method. [Refer: Joint ventures [member]; Unrecognised share of losses of joint ventures]

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The description of the nature of the entity's relationship with a joint venture (for example, describing the nature of the activities of the joint venture and whether they are strategic to the entity's activities). [Refer: Joint ventures [member]]

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The fair value of investments in associates if there are quoted market prices for the investment. [Refer: Associates [member]; Investments in associates]

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The amount of investments in associates accounted for using the equity method. [Refer: Associates [member]; Investments accounted for using equity method]

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The amount of investments in joint ventures accounted for using the equity method. [Refer: Joint ventures [member]; Investments accounted for using equity method]

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The proportion of ownership interest in a joint venture attributable to the entity. [Refer: Joint ventures [member]]

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The amount of the unrecognised share of associates' losses if the entity has stopped recognising its share of losses when applying the equity method. [Refer: Associates [member]]

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The amount of the unrecognised share of joint ventures' losses if the entity has stopped recognising its share of losses when applying the equity method. [Refer: Joint ventures [member]]

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