1001 - Document - Cover link:presentationLink link:definitionLink link:calculationLink 1002 - Statement - Statements of Net Assets Available For Benefits link:presentationLink link:definitionLink link:calculationLink 1003 - Statement - Statement of Changes in Net Assets Available For Benefits link:presentationLink link:definitionLink link:calculationLink 1004 - Disclosure - Description of Plan link:presentationLink link:definitionLink link:calculationLink 1005 - Disclosure - Summary of Significant Accounting Policies link:presentationLink link:definitionLink link:calculationLink 1006 - Disclosure - Fair Value Measurements link:presentationLink link:definitionLink link:calculationLink 1007 - Disclosure - Related Party Transactions link:presentationLink link:definitionLink link:calculationLink 1008 - Disclosure - Tax Status link:presentationLink link:definitionLink link:calculationLink 1009 - Disclosure - Risks And Uncertainties link:presentationLink link:definitionLink link:calculationLink 1010 - Disclosure - Schedule H, Line 4(i) Schedule of Assets (Held at End of Year) link:presentationLink link:definitionLink link:calculationLink 1011 - Disclosure - Summary of Significant Accounting Policies (Policies) link:presentationLink link:definitionLink link:calculationLink 1012 - Disclosure - Description of Plan - Additional Information (Detail) link:presentationLink link:definitionLink link:calculationLink 1013 - Disclosure - Fair Value Measurements - Summary of Fair Value of the Plan's Assets (Detail) link:presentationLink link:definitionLink link:calculationLink 1014 - Disclosure - Schedule H, Line 4(i) Schedule of Assets (Held at End of Year) (Detail) link:presentationLink link:definitionLink link:calculationLink 1015 - Disclosure - Schedule H, Line 4(i) Schedule of Assets (Held at End of Year) (Detail) Alternate link:presentationLink link:definitionLink link:calculationLink Cover [Abstract] EBP, Statement of Net Asset Available for Benefit [Table] Legal Entity [Axis] Entity [Domain] EBP 006 [Member] Document Information [Line Items] Document Type Amendment Flag Document Period End Date Document Fiscal Year Focus Document Fiscal Period Focus Entity Registrant Name Entity Central Index Key EBP, Statement of Net Asset Available for Benefit [Abstract] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Asset [Abstract] ASSETS EBP, Receivable [Abstract] Receivables EBP, Note Receivable from Participant Notes receivable from participants EBP, Employer Contribution, Receivable Employer contributions receivable EBP, Participant Contribution, Receivable Participant contributions receivable EBP, Receivable Total receivables EBP, Net Asset Available for Benefit NET ASSETS AVAILABLE FOR BENEFITS NET ASSETS AVAILABLE FOR BENEFITS, BEGINNING OF YEAR NET ASSETS AVAILABLE FOR BENEFITS, END OF YEAR EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Investments, at fair value EBP, Statement of Change in Net Asset Available for Benefit [Abstract] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment [Abstract] Investment income: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment Interest and dividend income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Net investment income EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Participants EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash Employer EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Rollover EBP, Change in Net Asset Available for Benefit, Increase from Contribution Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Interest income on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Shares Allocated for ESOP Other additions EBP, Change in Net Asset Available for Benefit, Increase Total additions EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] DEDUCTIONS FROM NET ASSETS ATTRIBUTED TO EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Benefit payments EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Administrative expenses EBP, Change in Net Asset Available for Benefit, Decrease from Shares Allocated for ESOP Other deductions EBP, Change in Net Asset Available for Benefit, Decrease Total deductions EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Net increase EBP, Description of Plan and Accounting Change [Abstract] EBP, Description of Plan [Table] EBP, Description of Plan [Line Items] EBP, Description of Plan [Text Block] Description Of Plan EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] EBP, Accounting Policy [Table] EBP, Accounting Policy [Line Items] EBP, Summary of Accounting Policy [Text Block] Summary Of Significant Accounting Policies EBP, Investment, Fair Value and NAV [Abstract] EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Line Items] EBP, Investment, Fair Value and NAV [Text Block] Fair Value Measurements EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Line Items] EBP, Related Party and Party-in-Interest Transactions [Text Block] Related Party Transactions EBP, Tax Status [Abstract] EBP, Tax Status [Table] EBP, Tax Status [Line Items] EBP, Tax Status [Text Block] Tax Status EBP, Risk and Uncertainty [Abstract] EBP, Risk and Uncertainty [Table] EBP, Risk and Uncertainty [Line Items] EBP, Risk and Uncertainty [Text Block] Risks And Uncertainties EBP, Schedule of Asset Held for Investment [Abstract] EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Line Items] Employee Benefit Plan Schedule Of Asset Held For Investments [Text Block] Employee Benefit Plan Schedule Of Asset Held For Investments Employee benefit plan schedule of asset held for investments. EBP, Basis of Accounting [Policy Text Block] Basis of accounting EBP, Use of Estimate [Policy Text Block] Use of estimates and assumptions EBP, Investment [Policy Text Block] Investment valuation and income recognition EBP, Note Receivable from Participant [Policy Text Block] Notes receivable from participants EBP, Payment to Participant [Policy Text Block] Benefit Payments EBP, Expense [Policy Text Block] Administrative expenses EBP, Employer Contribution, Matching Percentage EBP, employer contribution, matching percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage EBP, employer contribution, participant compensation matched, percentage EBP, Participant Contribution, Automatic, Deferral Rate EBP, participant contribution, automatic, deferral rate Employee Benefit Plan Employer Matching And Discretionary Contributions Percentage Employee benefit plan employer matching and discretionary contributions percentage Employee benefit plan employer matching and discretionary contributions percentage. EBP, Forfeited Nonvested Account EBP, forfeited nonvested account. EBP, Forfeited Nonvested Account, Decrease from Employer Contribution EBP, forfeited nonvested account, decrease from employer contribution EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount EBP, note receivable from participant, account, maximum borrowing, amount. EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage EBP, note receivable from participant, account, maximum borrowing, to total account, percentage. EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount EBP, note receivable from participant, account, minimum borrowing, amount. Employee Benefit Plan Terminates Participants Percentage Employee benefit plan terminates participants percentage Employee benefit plan terminates participants percentage. Employee Benefit Plan Lump Sum Payment Threshold EBP, Vested account lump sum threshold Employee Benefit Plan Lump Sum Payment Threshold. EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage Employee benefit plan participant contribute compensation percentage Employee Benefit Plan Vested Amount Threshold EBP, vested amount of direct rollover if no election Employee Benefit Plan Vested Amount Threshold Statistical Measurement [Axis] Statistical Measurement [Domain] Maximum [Member] Minimum [Member] Vesting Perid [Axis] Vesting Period [Domain] Until Year 2 [Member] Year 0-2 [Member] Year Three [Member] Year 3 [Member] Year Three. Investment Type [Axis] Investments [Domain] Short Term Investment Fund [Member] Short term investment fund [Member] Short term investment fund. Registered Investment [Member] Registered investment companies [Member] Registered investment. Common Collective Trust [Member] Common/collective trusts [Member] EBP, Employer, Common Stock [Member] CIBC common stock [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Investment, Identifier [Axis] Investment, Issuer Name [Axis] Investment, Issuer Name [Domain] Stock Fund [Member] EBP, Participant-Directed and Nonparticipant-Directed Status [Axis] EBP, Participant-Directed and Nonparticipant-Directed Status [Domain] Entity Tax Identification Number EBP, Plan Number EBP, Investment, Issuer Name [Extensible Enumeration] EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Investment, Number of Shares EBP, Investment, Current Value, Type [Extensible Enumeration] EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution EBP, Asset Held for Investment EBP, Asset Held for Investment, Participant Loan, Interest Rate EBP, Asset Held for Investment, Party-in-Interest [true false] EBP, Participant-Directed [Member] American Funds EUPAC Fund ClassR6 [Member] AMG Times Square Mid Cap Growth Fund [Member] Calvert Balanced Fund [Member] CIBC stock [Member] Cohen Steers Realty Shares Fund [Member] DFA US Targeted Value Portfolio [Member] Dodge Cox Stock Fund [Member] Fidelity Emerging Markets Fund [Member] JPMorgan Large Cap Growth Fund [Member] Loomis Sayles Small Cap Growth Fund [Member] Nuveen Core Impact Bond Fund [Member] Parnassus Core Equity Fund [Member] Prudential Core Plus Bond Fund [Member] Vanguard Cash Reserves Federal MM Fund Admiral Shares [Member] Vanguard HighYield Corporate Fund Admiral Shares [Member] Vanguard Institutional Index Fund Instl Plus Shares [Member] Vanguard MidCap Index Fund Institutional Shares [Member] Vanguard Retirement Savings Trust III [Member] Vanguard SmallCap Index Fund Institutional Shares [Member] Vanguard Target Retirement 2020 Trust I [Member] Vanguard Target Retirement 2025 Trust I [Member] Vanguard Target Retirement 2030 Trust I [Member] Vanguard Target Retirement 2035 Trust I [Member] Vanguard Target Retirement 2040 Trust I [Member] Vanguard Target Retirement 2045 Trust I [Member] Vanguard Target Retirement 2050 Trust I [Member] Vanguard Target Retirement 2055 Trust I [Member] Vanguard Target Retirement 2060 Trust I [Member] Vanguard Target Retirement 2065 Trust I [Member] Vanguard Target Retirement 2070 Trust I [Member] Vanguard Target Retirement Income and Growth Trust I [Member] Vanguard Target Retirement Income Trust I [Member] Vanguard Total Bond Market Index Fund [Member] Vanguard Total International Stock Index Fund [Member] Victory Sycamore Est Value Fund [Member]