Business Acquisition [Axis]
Business Acquisition [Axis]
Casualty and other
Casualty And Other
Other expenses including costs associated with casualty, environmental, insurance and operating taxes.
Real estate [Member]
Defined Benefit Plan, Real Estate [Member]
Revision of Prior Period [Axis]
Revision of Prior Period [Axis]
Increase in other cost
Defined Benefit Plan, Increase (Decrease) In Other Cost
Defined Benefit Plan, Increase (Decrease) In Other Cost
Indemnification Agreement [Member]
Indemnification Agreement [Member]
Foreign
Current Foreign Tax Expense (Benefit)
Foreign currency
Foreign Currency Transactions and Translations Policy [Policy Text Block]
Specialty Portfolio [Member]
Specialty Portfolio [Member]
Specialty Portfolio
Total debt, gross
Debt outstanding
Long-Term Debt, Gross
Equipment Loans And Other [Member]
Equipment Loans And Other [Member]
Equipment Loans And Other
Net
Finance leases
Finance Lease, Right-of-Use Asset, after Accumulated Amortization
Non-freight [Member]
Non-freight [Member]
Assets held for sale
Disposal Group, Including Discontinued Operation, Other Assets, Current
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment [Abstract]
February 1, 2023 - January 31, 2024 [Member]
Stock Repurchase Program, Period In Force, Two [Member]
Stock Repurchase Program, Period In Force, Two
Deferred income tax expense
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Global Macro Funds [Member]
Global Macro Funds [Member]
A portfolio of units of externally managed hedge funds investing mainly in global macro funds.
Information for the pension plans with an accumulated benefit obligation in excess of plan assets
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Table Text Block]
Alternative Risk Premia [Member]
Risk Factor Allocation
A portfolio of units of externally managed funds, where each asset contribute equally to the overall risk
Canadian National series, 7.63% 30-year debentures [Member]
CNR 2023 Debentures [Member]
This element includes 30-year debentures due 2023.
Debt Instrument [Axis]
Debt Instrument [Axis]
Present value of lease payments
Finance leases
Finance lease liabilities
Finance Lease, Liability
Dividends paid
Payments of Ordinary Dividends, Common Stock
Prior service credit arising during the period, after tax
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Tax
U.S. Dollar [Member]
Foreign Currency Risk Exposure to U.S. Dollar [Member]
Fair value of plan assets by class
Schedule of Defined Benefit Plans Disclosures [Table Text Block]
Debt, excluding finance leases, fair value
Debt Instrument, Fair Value Disclosure
Foreign Currency Risk Exposure [Axis]
Foreign Currency Risk Exposure [Axis]
Public Equities, Foreign Exchange Forwards [Member]
Public Equities, Foreign Exchange Forwards [Member]
Public Equities, Foreign Exchange Forwards
Absolute Return Funds, Options [Member]
Absolute Return Funds, Options [Member]
Absolute Return Funds, Options
Additional paid-in capital
Additional Paid in Capital
2026
Finance Lease, Liability, to be Paid, Year Four
Stock options exercised (in shares)
Exercised (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period
Operating leases
Operating Lease, Weighted Average Discount Rate, Percent
Multiemployer plan employer contribution rate per month
Multiemployer Plan Employer Contribution Rate Per Month
Monthly contribution rate per employee for the multi-employer plan.
Disbursements
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Decrease for Settlement
Other Current Assets [Member]
Other Current Assets [Member]
Guarantee Obligations [Member]
Guarantee Obligations [Member]
Awards Granted Prior To 2020 [Member]
Awards Granted Prior To 2020 [Member]
Awards Granted Prior To 2020
Alternative Risk Premia [Member]
Alternative Risk Premia [Member]
Alternative Risk Premia
Private Equities, Foreign Exchange Forwards [Member]
Private Equities, Foreign Exchange Forwards [Member]
Private Equities, Foreign Exchange Forwards
Rolling Stock [Member]
Rolling Stock [Member]
Long lived depreciable railroad cars and locomotives used for the primary purpose of rail transportation.
2025
Finance Lease, Liability, to be Paid, Year Three
Units excluded from the calculation as their inclusion would not have a dilutive effect (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Equities [Member]
Defined Benefit Plan, Equity Securities [Member]
Operating leases
Lessee, Operating Lease, Liability, to be Paid [Abstract]
Share Repurchase Program [Domain]
Share Repurchase Program [Domain]
2028 & thereafter
Lessee, Operating Lease, Liability, to be Paid, after Year Five
Loss recovery, after-tax
Long Lived Assets Held-For-Sale, Loss Recovery, After-Tax
Long Lived Assets Held-For-Sale, Loss Recovery, After-Tax
Number of stock options outstanding and exercisable by range of exercise price and their related intrinsic value, and for options outstanding, the weighted-average years to expiration
Share-Based Payment Arrangement, Option, Exercise Price Range [Table Text Block]
Equity Component [Domain]
Equity Component [Domain]
Personal injury and other claims provisions
Loss Contingency, Accrual, Noncurrent
Subsequent Event Type [Domain]
Subsequent Event Type [Domain]
Number of options outstanding (in shares)
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding
Tax positions related to the current year
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions
Weighted average exercise price of options outstanding (in dollars per share)
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price
Amortization of right-of-use assets
Finance Lease, Right-of-Use Asset, Amortization
Uncommitted Bilateral Letter of Credit Facilities [Member]
Uncommitted Bilateral Letter of Credit Facilities [Member]
Going concern basis excess (deficit) funded status
Going Concern Defined Benefit Plan Funded Status Of Plan
The going concern excess (deficit) funded status is measured as the difference between the fair value of plan assets and the benefit obligation based on an actuarial valuation, for funding purposes. The excess (deficit) is based on current projected results of actuarial funding valuations on a going concern basis. Actuarial valuations for funding purposes are subject to revaluation on an annual basis.
Gain on derivative instruments, net, pretax
Gain on Derivative Instruments, Pretax
Total plan assets
Fair value of plan assets at beginning of year
Fair value of plan assets at end of year
Defined Benefit Plan, Plan Assets, Amount
Loss recovery, pre-tax
Long Lived Assets Held-For-Sale, Loss Recovery, Pre-Tax
Long Lived Assets Held-For-Sale, Loss Recovery, Pre-Tax
Number of commodity groups
Number Of Commodity Groups
Number Of Commodity Groups
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]
Foreign exchange
Accrual for Environmental Loss Contingencies, Foreign Currency Translation Gain (Loss)
Supplemental cash flow information
Supplemental Cash Flow Information [Abstract]
Fair value of units vested
Employee Stock Ownership Plan (ESOP), Fair Value Of Shares Vested
Employee Stock Ownership Plan (ESOP), Fair Value Of Shares Vested
Weighted average exercise price of options forfeited/cancelled (in dollars per share)
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price
Unrecognized compensation costs, awards other than options
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount
Plan Name [Domain]
Plan Name [Domain]
Surety and Other Bond [Member]
Surety Bond [Member]
Outstanding borrowings under the revolving credit facility
Outstanding borrowings
Long-Term Line of Credit
Commercial paper, weighted average interest rate
Commercial Paper, Weighted Average Interest Rate
Weighted average interest rate of commercial paper outstanding.
Accrual for Environmental Loss Contingencies [Roll Forward]
Accrual for Environmental Loss Contingencies [Roll Forward]
Metals And Minerals [Member]
Metals And Minerals [Member]
Metals And Minerals [Member]
Award Type [Axis]
Award Type [Axis]
Long Lived Assets Held-for-sale by Asset Type [Axis]
Long-Lived Assets Held-for-sale by Asset Type [Axis]
Actuarial gain
Actuarial gain on projected benefit obligation
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)
2027
Defined Benefit Plan, Expected Future Benefit Payment, Year Five
Total lease right-of-use assets
Lease, Right-Of-Use Asset
Lease, Right-Of-Use Asset
Settlements
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities
Net change in pension and other postretirement benefit plans
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax
Operating leases
Operating lease liabilities
Operating Lease, Liability, Current
Fixed Income Fund [Member]
Fixed Income Fund [Member]
A portfolio of units of externally managed hedge funds investing mainly in fixed income funds.
Cash paid for amounts included in the measurement of lease liabilities ($)
Cash Flow, Operating Activities, Lessee [Abstract]
Pension Plan amortization of cumulative net actuarial gains and losses excess threshold
Pension Plan Amortization Threshold Gain Loss
Pension Plan's amortization of cumulative net actuarial gains and losses percentage in excess of, the greater of the beginning of year balances of the projected benefit obligation or market-related value of plan assets, over the expected average remaining service life of the employee group covered by the plans.
Forfeited/Cancelled (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested Options Forfeited, Number of Shares
All Currencies [Domain]
All Currencies [Domain]
CN Pension Plan [Member]
CN Pension Plan [Member]
Emerging Market Debt, Foreign Exchange Forward [Member]
Emerging Market Debt, Foreign Exchange Forward [Member]
Emerging Market Debt, Foreign Exchange Forward
Canadian Equities [Member]
Canadian Equities [Member]
This category includes information about ownership interests or the right to acquire ownership interests in Canadian corporations and other legal entities which ownership interest is represented by shares of common or preferred stock (which is neither mandatorily redeemable no redeemable at the option of the holder), convertible securities, stock rights, or stock warrants.
Other - Operating assets, at cost [Member]
Operating Assets At Cost [Member]
Operating assets required to administer the Trusts' investment assets and the plans' benefit and funding activities valued at cost.
Operating leases
Operating Lease, Weighted Average Remaining Lease Term
Unamortized government assistance
Government Assistance, Unamortized Amount
Government Assistance, Unamortized Amount
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Equipment loans and other
Loans Payable
Estimated future benefit payments
Schedule of Expected Benefit Payments [Table Text Block]
Absolute Return, Specialty Portfolio Strategy [Member]
Absolute Return, Specialty Portfolio Strategy [Member]
Absolute Return, Specialty Portfolio Strategy
Prior service credit arising during the period, before tax
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax
Fair Value Hierarchy and NAV [Domain]
Fair Value Hierarchy and NAV [Domain]
Canadian National series, 3.20% 30-year notes [Member]
CNR 2046 Notes [Member]
This element includes 30-year notes due 2046.
Revolving Credit Facility [Member]
Revolving Credit Facility [Member]
Canadian National series, 2.75% 10-year notes [Member]
CNR 2026 Notes [Member]
This element includes 10-year notes payable due 2026.
Current portion - End of year
Loss Contingency, Accrual, Current
Revenues
Revenue from Contract with Customer [Policy Text Block]
Current income tax expense (recovery)
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Accounting Standards Update and Change in Accounting Principle [Abstract]
Document Type
Document Type
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Debt
Long-Term Debt [Text Block]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Accounts Payable and Other [Member]
Accounts Payable and Accrued Liabilities [Member]
Exchange rates
Derivative, Forward Exchange Rate
Corridor percentage
Defined Benefit Plan, Plan Assets, Market-Related Value, Corridor Percentage
Defined Benefit Plan, Plan Assets, Market-Related Value, Corridor Percentage
Weighted-average grant date fair value at beginning of period (in dollars per share)
Weighted-average grant date fair value at end of period (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value
Finance leases
Finance Lease, Liability, to be Paid [Abstract]
Schedule of accounts receivable securitization
Schedule Of Accounts Receivable Securitization [Table Text Block]
Schedule Of Accounts Receivable Securitization [Table Text Block]
Deferred income taxes
Total deferred income tax expense
Deferred Income Tax Expense (Benefit)
Pension asset
Noncurrent assets - Pension asset
Assets for Plan Benefits, Defined Benefit Plan
Exercise Price Range [Axis]
Exercise Price Range [Axis]
Material and supplies
Increase (Decrease) in Materials and Supplies
Other liabilities and deferred credits
Other Liabilities Disclosure [Text Block]
PSU-ROIC and PSU-TSR [Member]
Performance Share Unit ROIC And Performance Share Unit TSR [Member]
Performance Share Unit ROIC And Performance Share Unit TSR [Member]
Assumptions used in valuation of stock-based compensation awards, other than stock options
Schedule Of Share Based Payment Award Valuation Assumptions And Compensation Cost [Table Text Block]
Tabular disclosure of information about share-based compensation plans that may include, but is not limited to: (a) the total compensation cost recognized over requisite service period and the total compensation cost related to nonvested awards not yet recognized and the weighted-average period over which it is expected to be recognized, (b) expected term of share options and similar instruments, (c) expected volatility of the entity's shares, (d) expected dividends, (e) risk-free rate(s), and (f) discount for post-vesting restrictions.
Maturity Less Than Ninety Days [Member]
Maturity Less Than Ninety Days [Member]
Maturity Less Than Ninety Days [Member]
Derivative instruments total before tax
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax
Refund of advance for acquisition
Refund Of Advances For Business Acquisition
Refund Of Advances For Business Acquisition
Foreign exchange gain (loss) on translation of US dollar-denominated debt designated as a hedge of the net investment in foreign operations, income tax recovery (expense)
Other Comprehensive Income, Foreign Currency Gain (Loss) on Translation of Foreign Currency Denominated Long-term Debt Designated as a Hedge of Net Investment in Foreign Subsidiaries, Tax
Amount of tax expense (benefit) allocated to other comprehensive income (loss) arising from gain (loss) on translation of foreign currency denominated long-term debt designated as a hedge of net investment in foreign subsidiaries.
Schedule of contract liabilities
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]
Retirement Plan Name [Domain]
Retirement Plan Name [Domain]
Income Tax Examination [Table]
Income Tax Examination [Table]
Income taxes receivable, CARES Act
Income Taxes Receivable, Reclassification Of Deferred Income Tax Asset, CARES Act
Income Taxes Receivable, Reclassification Of Deferred Income Tax Asset, CARES Act
Additional income, after-tax
Business Combination, Income After Tax
Business Combination, Income After Tax
Foreign exchange loss on translation of net investment in foreign operations, income tax recovery (expense)
Other Comprehensive Income, Foreign Currency Gain (Loss) on Translation of Net Investment in Foreign Operations, Tax
Amount of tax expense (benefit) allocated to other comprehensive income (loss) arising from gain (loss) on foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity.
Multiemployer Plans [Line Items]
Multiemployer Plan [Line Items]
Resource and royalties [Member]
Oil and Gas [Member]
Settlement from the Share Trusts in next fiscal year (in shares)
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Settled By Units From Share Trust
Number of units to be settled from the Share Trusts in the next fiscal year.
Private debt [Member]
Private Debt [Member]
Automotive [Member]
Automotive [Member]
Automotive [Member]
Debt Disclosure [Abstract]
Debt Disclosure [Abstract]
Accounts receivable
Accounts Receivable [Policy Text Block]
Employer contributions
Defined Benefit Plan, Plan Assets, Contributions by Employer
Deferred tax expense
Income Tax Examination, Penalties and Interest Expense
Income tax recovery (expense)
Income tax expense
Income tax recovery (expense)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent
Net cash used in financing activities
Net Cash Provided by (Used in) Financing Activities
Material and supplies
Materials, Supplies, and Other
Accounting Policies [Abstract]
Accounting Policies [Abstract]
Variable lease cost
Variable Lease, Cost
Fair value of plan assets
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets
Shareholders' equity
Stockholders' Equity Attributable to Parent [Abstract]
Other current assets
Total other current assets
Prepaid Expense and Other Assets, Current
Cumulative Effect, Period of Adoption [Domain]
Cumulative Effect, Period of Adoption [Domain]
Foreign
Deferred Tax Assets Liabilities Foreign Net
For entities that net deferred tax assets and tax liabilities, represents the unclassified net amount of deferred tax assets and liabilities as of the balance sheet date for US and other foreign operations, which result from applying the applicable enacted tax rate to net temporary differences and carryforwards pertaining to assets or liabilities.
Interest cost
Defined Benefit Plan, Interest Cost
Private Equities [Member]
Private Equity Funds [Member]
Finance leases
Finance Lease, Liability, Noncurrent
Assumptions used in valuation of stock option awards
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
Canadian National series, 3.50% 30-year notes [Member]
CNR 2042 Notes [Member]
This element includes 30-year notes payable due 2042.
Debt instrument, number of extension requests per year
Debt Instrument, Number Of Extension Requests Per Year
Debt Instrument, Number Of Extension Requests Per Year
Tax information on a domestic and foreign basis
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
Unrecognized compensation cost, period of recognition
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition
Weighted-average years to expiration of options exercisable
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term
Weighted average term
Derivative, Weighted Average Term
Derivative, Weighted Average Term
Derivative Contract [Domain]
Derivative Contract [Domain]
Revolving Credit Facility, Accordion Feature [Member]
Revolving Credit Facility, Accordion Feature [Member]
Revolving Credit Facility, Accordion Feature [Member]
Compensation reserves
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation
Entity Registrant Name
Entity Registrant Name
Employee injuries, United States [Member]
Employee injuries, United States
Information about employee injuries in United States.
Weighted-average price per share (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Per Share Weighted Average Price of Shares Purchased
2026
Defined Benefit Plan, Expected Future Benefit Payment, Year Four
Subsequent event
Subsequent Events [Text Block]
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table]
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table]
Ceiling of exercise price range (in dollars per share)
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit
Excess tax benefit recognized in income
Employee Service Share-based Compensation, Excess Tax Benefit from Compensation Expense
Stock-based compensation expense and other
APIC, Share-Based Payment Arrangement, Recognition and Exercise
Benefit payments, settlements and transfers
Defined Benefit Plan, Benefit Obligation, Benefits Paid
Pensions and other postretirement benefits
Retirement Benefits [Text Block]
Leases [Abstract]
Leases [Abstract]
Foreign exchange gain (loss) on translation of US dollar-denominated debt designated as a hedge of the net investment in foreign operations, before tax
Other Comprehensive Income, Foreign Currency Gain (Loss) on Translation of Foreign Currency Denominated Long-term Debt Designated as a Hedge of Net Investment in Foreign Subsidiaries, Before Reclassification and Tax
Amount before tax and reclassification adjustments of gain (loss) on translation of foreign currency denominated long-term debt designated as a hedge of net investment in foreign subsidiaries.
Principles of consolidation
Consolidation, Policy [Policy Text Block]
Minimum [Member]
Minimum [Member]
Range of Exercise Prices 5 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range 5 [Member]
One range (Range 5) in a series of customized ranges of exercise prices for the purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards for this range.
Actual contributions for all pension plans contributed in next fiscal year
Defined Benefit Plan Actual Employer Contributions In Next Fiscal Year
The employer's actual contributions made to the plan during the next fiscal year beginning after the date of the latest statement of financial position (as at filing date).
Derivative instruments total net of tax
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax
DSU [Member]
Deferred Share Units [Member]
Units awarded to employees under the Company's Voluntary Incentive Deferral Plan.
Income Tax Examination [Line Items]
Income Tax Examination [Line Items]
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Abstract]
Proceeds received
Proceeds from Accounts Receivable Securitization
Gain on disposal of land
Nonoperating Gains (Losses)
Weighted-average price per share (including brokerage fees) (in dollars per share)
Treasury Stock Acquired, Average Cost Per Share
Unrecognized deferred income tax asset on unrealized foreign exchange loss recorded in AOCI
Unrecognized deferred income tax asset on unrealized foreign exchange loss recorded in AOCI
Amount of unrecognized deferred tax asset attributable to deductible temporary differences from unrealized losses on foreign currency transactions.
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Imputed interest rate
Imputed Interest Rate Percentage on Discounted Debt
Interest rate applied to the outstanding amount of debt to impute the amount of interest included as part of the principal.
Weighted-average years to expiration of options outstanding
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term
Accrued interest
Interest Payable, Current
Range of Exercise Prices 4 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range 4 [Member]
One range (Range 4) in a series of customized ranges of exercise prices for the purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards for this range.
Foreign
Deferred Foreign Income Tax Expense (Benefit)
Derivative financial instruments
Derivatives, Policy [Policy Text Block]
Units granted in period (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period
Increase due to consideration received, net of revenue recognized
Contract With Customer, Liability, Increase From Cash Receipts
Contract With Customer, Liability, Increase From Cash Receipts
Concentration Risk Benchmark [Axis]
Concentration Risk Benchmark [Axis]
Canadian National series, 3.20% 10-year notes [Member]
CNR Two Thousand Twenty-Eight Ten Year Notes [Member]
CNR Two Thousand Twenty-Eight Ten Year Notes [Member]
Cash contribution to pension plan, expected to be
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year
Company contributions (in shares)
Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Contributions In Period
Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Contributions In Period
Use of estimates
Use of Estimates, Policy [Policy Text Block]
Acquisition
Business Combination Disclosure [Text Block]
Advance paid
Business Combination, Advance Paid To Acquiree
Business Combination, Advance Paid To Acquiree
Concentration of risk
Concentration Risk, Percentage
Solvency basis excess (deficit) funded status
Defined Benefit Plan Funded Solvency Basis Status Of Plan
The excess (deficit) funded status is measured as the difference between the fair value of plan assets and the benefit obligation based on an actuarial valuation, for funding purposes. The excess (deficit) is based on current projected results of actuarial funding valuations on a solvency basis. Actuarial valuations for funding purposes are subject to revaluation on an annual basis.
Total net deferred income tax liability
Deferred Income Tax Liabilities, Classification [Abstract]
Deferred Income Tax Liabilities, Classification
Accounts payable and other
Increase (Decrease) in Accounts Payable and Accrued Liabilities
Income taxes
Income Tax Disclosure [Text Block]
Weighted average interest rate
Debt, Weighted Average Interest Rate
Advance for acquisition and other transaction-related costs
Payments Of Advances And Other Transaction Costs For Business Acquisition
Payments Of Advances And Other Transaction Costs For Business Acquisition
Aggregate intrinsic value of share units outstanding
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding
Cash and short-term investments [Member]
Defined Benefit Plan, Cash and Cash Equivalents [Member]
Credit Facility [Domain]
Credit Facility [Domain]
Units forfeited (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Forfeitures
Basic (in dollars per share)
Basic earnings per share (in dollars per share)
Earnings Per Share, Basic
Amortization of gain on treasury lock, income tax recovery (expense)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax
Canadian National series, 2.75% 7-year notes [Member]
CNR 2021 Notes 7Yr [Member]
This element includes 7 year notes payable due 2021.
Accumulated other comprehensive loss, before tax, beginning balance
Accumulated other comprehensive loss, before tax, ending balance
AOCI before Tax, Attributable to Parent
Period of continuance employment to be eligible to exercise stock options
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Requisite Service Period
Revenues from External Customers [Line Items]
Revenues from External Customers and Long-Lived Assets [Line Items]
Fair value of awards vested during the period
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value
Accounting Standards Update and Change in Accounting Principle [Table]
Accounting Standards Update and Change in Accounting Principle [Table]
Derivative instruments
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax
Schedule of Accounts, Notes, Loans and Financing Receivable [Table]
Schedule of Accounts, Notes, Loans and Financing Receivable [Table]
Prepaid expenses
Prepaid Expense, Current
Actuarial gain (loss) arising during the year, before tax
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax
Change In Methodology Of Net Periodic Pension Cost (Income) [Member]
Change In Methodology Of Net Periodic Pension Cost (Income) [Member]
Change In Methodology Of Net Periodic Pension Cost (Income)
Property, Plant and Equipment [Table]
Property, Plant and Equipment [Table]
Changes in operating assets and liabilities:
Increase (Decrease) in Operating Capital [Abstract]
Investments
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
Lease liabilities
Lease Liabilities, Lessee [Abstract]
Lease Liabilities, Lessee [Abstract]
2027
Finance Lease, Liability, to be Paid, Year Five
Maximum percentage of gross salary eligible employees can subscribe to purchase shares of Company's common stock on the open market
Share-Based Compensation Arrangement by Share-Based Payment Award, Maximum Employee Subscription Rate
Other comprehensive income
Other comprehensive income (loss)
Other comprehensive loss
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Repurchase of common shares
Payments for Repurchase of Common Stock
Commercial paper
Commercial paper, outstanding
Commercial Paper
2028 & thereafter
Long-Term Debt, Maturity, after Year Five
Canadian National series, 3.65% 30-year notes [Member]
CNR Two Thousand Forty-Eight Thirty Year Notes [Member]
CNR Two Thousand Forty-Eight Thirty Year Notes [Member]
Income taxes
Income Tax, Policy [Policy Text Block]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards [Line Items]
Commercial paper, maturity
Commercial Paper, Term
Period of time between issuance and maturity of commercial paper, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
Track and Roadway [Member]
Track and Roadway [Member]
Long-lived depreciable assets such as tracks and ties as well as land assets, used for the primary purpose of rail transportation.
Canadian National series, 6.20% 30-year notes [Member]
CNR 2036 Notes [Member]
This element includes 30-year notes payable due 2036.
Current assets
Assets, Current [Abstract]
Recognized accrued interest and penalties
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Revenue by geographic areas
Revenue from External Customers by Geographic Areas [Table Text Block]
Retained earnings
Retained Earnings (Accumulated Deficit)
Share purchases by Share Trusts (in shares)
Number of shares purchased on behalf of employees (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Purchased for Award
Settlement loss
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement
Downside Protection [Member]
Downside Protection [Member]
Downside Protection
Schedule of Finite-Lived Intangible Assets [Table]
Schedule of Finite-Lived Intangible Assets [Table]
Scenario [Domain]
Scenario [Domain]
Personal injury and other claims
Personal Injury And Other Claims Contingency Policy [Policy Text Block]
Description of the accrual policy for personal injury and other claims loss contingencies (general and professional liability) which may include the method for calculating incurred but not reported (IBNR) claims, the use of actuarial and individual case-based assumptions, whether the accrual has been discounted, the types of costs included in the accrual (for example, legal costs) and other significant estimates used to determine the accrued liability.
Fair Value, Recurring [Member]
Fair Value, Recurring [Member]
Weighted average exercise price of options exercisable at end of period (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price
PSU-ROIC and PSU-TSR [Member]
PSU-ROIC and PSU-TSR [Member]
PSU-ROIC and PSU-TSR
Income before income taxes
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest [Abstract]
Document Fiscal Year Focus
Document Fiscal Year Focus
Defined Benefit Plan, Plan Assets, Category [Domain]
Defined Benefit Plan, Plan Assets, Category [Domain]
Financing cash outflows from finance leases
Finance Lease, Principal Payments
Fair Value Hierarchy and NAV [Axis]
Fair Value Hierarchy and NAV [Axis]
Change in accounting policy
Recent accounting pronouncements
Accounting Standards Update and Change in Accounting Principle [Text Block]
Loss Contingencies [Table]
Loss Contingencies [Table]
Total current income tax expense
Current Income Tax Expense (Benefit)
Assets held for sale
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]
Accounts receivable
Accounts Receivable, after Allowance for Credit Loss, Current [Abstract]
Stock-based compensation awards activity, other than stock options
Share-Based Payment Arrangement, Activity [Table Text Block]
Purchase of common shares for settlement of equity settled awards
Payments for Repurchase of Other Equity
Cost method investments
Equity Securities without Readily Determinable Fair Value, Amount
Outstanding common shares (in shares)
Common Stock, Shares, Outstanding
Government assistance, amortization
Government Assistance, Amortization Amount
Government Assistance, Amortization Amount
Investments
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
Goodwill
Goodwill
Canadian National series, 3.95% 30-year notes [Member]
Cnr 2045 Notes [Member]
This element includes 30-year notes payable due 2045.
Property, Plant and Equipment, Type [Axis]
Long-Lived Tangible Asset [Axis]
Category of Item Purchased [Axis]
Category of Item Purchased [Axis]
Actual return on plan assets
Actual return on plan assets
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)
Equity Funds [Member]
Equity Funds [Member]
Income tax expense
Income tax expense
Income Tax Expense (Benefit)
Geographical [Domain]
Geographical [Domain]
Deferred income taxes
Deferred Income Tax Liabilities, Net
Balance Sheet Location [Domain]
Balance Sheet Location [Domain]
Other Award Type [Domain]
Other Award Type [Domain]
Performance Share Unit Awards
Canadian National series, 3.05% 30-year notes [Member]
CNR Two Thousand Fifty Thirty Year Notes [Member]
CNR Two Thousand Fifty Thirty Year Notes [Member]
Share Settlements by Share Trusts [Abstract]
Share Settlements by Share Trusts [Abstract]
Loss Contingencies [Line Items]
Loss Contingencies [Line Items]
2023
Defined Benefit Plan, Expected Future Benefit Payment, Year One
Unrealized foreign exchange losses
Deferred Tax Assets, Unrealized Currency Losses
Accounts payable and other
Total accounts payable and other
Accounts Payable and Accrued Liabilities, Current
Noncurrent
Noncurrent Liability, Lessee [Abstract]
Noncurrent Liability, Lessee [Abstract]
Canadian National series, 3.60% 30-year notes [Member]
CNR Two Thousand Forty Nine Notes [Member]
CNR Two Thousand Forty Nine Notes [Member]
Common shares
Common Stock, Value, Issued
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Business Acquisition, Acquiree [Domain]
Business Acquisition, Acquiree [Domain]
Bonds and derivative financial instruments [Member]
Bonds And Derivative Financial Instruments [Member]
Bonds And Derivative Financial Instruments [Member]
Long-term receivables
Other Assets, Miscellaneous
Other postretirement benefits liability
Current liabilities
Liability, Defined Benefit Plan, Current
2020 Grant Year [Member]
Granted Year 2020 [Member]
Granted Year 2020 [Member]
Accumulated benefit obligation
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation
Other [Member]
Other Capitalized Property Plant and Equipment [Member]
Cash, cash equivalents, restricted cash, and restricted cash equivalents, beginning of year
Cash, cash equivalents, restricted cash, and restricted cash equivalents, end of year
Cash, cash equivalents, restricted cash, and restricted cash equivalents, end of year
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents
Foreign
Income (Loss) from Continuing Operations before Income Taxes, Foreign
Current liabilities
Liabilities, Current [Abstract]
Issuance of common shares for stock options exercised
Proceeds from stock options exercised
Proceeds from Stock Options Exercised
Change in Accounting Principle, Type [Domain]
Change in Accounting Principle, Type [Domain]
Other
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount
Grant price (in dollars per share)
Stock Option Grant Price
The stock option grant price used in assumptions in determining the value of awards granted to employees.
Current portion - End of year
Contract liabilities
Contract with Customer, Liability, Current
Interest on lease liabilities
Finance Lease, Interest Expense
Retirement Plan Type [Domain]
Retirement Plan Type [Domain]
2019 Grant Year [Member]
Granted Year 2019 [Member]
Granted Year 2019
Amendment Flag
Amendment Flag
Intangible asset useful life
Finite-Lived Intangible Asset, Useful Life
Operating lease cost
Operating Lease, Cost
Repayment
Repayments of Accounts Receivable Securitization
Options exercisable
Options Exercisable [Abstract]
Grant date fair value of option awards in period
Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Grant Date Fair Value Total
The grant date fair value of options awarded during the period determined using valuation models.
Deferred income tax assets
Components of Deferred Tax Assets [Abstract]
Amounts recognized in accumulated other comprehensive loss
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]
Intangible Assets
Goodwill and Intangible Assets Disclosure [Abstract]
Other long-term assets
Other Assets, Noncurrent
Intermodal [Member]
Intermodal [Member]
Intermodal [Member]
Stock options additional disclosures
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Options exercisable at end of period (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number
Investment redemption, notice period
Defined Benefit Plan, Investments, Entities That Calculate Net Asset Value Per Share, Investment Redemption, Notice Period
Defined Benefit Plan, Investments, Entities That Calculate Net Asset Value Per Share, Investment Redemption, Notice Period
Canadian National series, 6.71% Puttable Reset Securities PURS [Member]
CNR 2036 Puttable Reset Securities [Member]
This element includes puttable reset securities PURSsm due 2036.
Resource and Royalties [Member]
Resource And Royalties [Member]
Resource And Royalties
Purchased services and material
Purchased Services And Material
Materials and contracted services to maintain infrastructure and equipment and terminal services at intermodal and automotive facilities.
Operating lease right-of-use assets
Deferred Tax Liabilities, Operating Lease, Right-Of-Use Asset
Deferred Tax Liabilities, Operating Lease, Right-Of-Use Asset
Accumulated Other Comprehensive Income (Loss) [Table]
Accumulated Other Comprehensive Income (Loss) [Table]
Stock-based compensation liability outstanding
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Share Based Liability Outstanding
The stock-based compensation liability outstanding related to deferred share units.
Environmental matters
Accrual for Environmental Loss Contingencies Disclosure [Abstract]
Provision for personal injury and other claims
Schedule of Loss Contingencies by Contingency [Table Text Block]
Information Technology [Member]
Technology Equipment [Member]
Domestic
Deferred Federal, State and Local, Tax Expense (Benefit)
Roll forward of outstanding PSUs
Roll forward of outstanding DSUs
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Weighted-average grant date fair value of units settled in period (in dollars per share)
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Settled, Weighted Average Grant Date Fair Value
The weighted-average grant date fair value of units settled during the period.
Currency [Axis]
Currency [Axis]
Operating cash outflows from operating leases
Operating Lease, Payments
Labor and fringe benefits
Labor and Related Expense
Repayment of debt
Repayments of Long-Term Debt
Increase in discount rate
Increase (decrease) in discount rate
Defined Benefit Plan, Change In Discount Rate
Defined Benefit Plan, Change In Discount Rate
Stock Options [Member]
Stock Option Awards [Member]
Share-Based Payment Arrangement, Option [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Expected stock price volatility
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate
Purchases
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase for Purchase
Allowance for credit losses
Accounts Receivable, Allowance for Credit Loss, Current
Stock options exercised
Stock Issued During Period, Value, Stock Options Exercised
Schedule of Guarantor Obligations [Table]
Schedule of Guarantor Obligations [Table]
Statement of Comprehensive Income [Abstract]
Statement of Comprehensive Income [Abstract]
Maximum [Member]
Maximum [Member]
Actuarial gain for increase in plan assets
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) for Plan Assets
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) for Plan Assets
Schedule of Business Acquisitions, by Acquisition [Table]
Schedule of Business Acquisitions, by Acquisition [Table]
Repurchase of common shares
Amount of repurchase (including brokerage fees)
Stock Repurchased and Retired During Period, Value
Cash and cash equivalents
Cash and cash equivalents, end of year
Cash and Cash Equivalents, at Carrying Value
Gain (loss) on equity investment with readily determinable fair values
Equity Securities, FV-NI, Gain (Loss)
Assets held for sale
Assets Held-For-Sale Disclosure [Text Block]
Assets Held-For-Sale Disclosure
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Government Assistance, Type [Axis]
Government Assistance, Type [Axis]
Business Acquisition [Line Items]
Business Acquisition [Line Items]
Measurement Frequency [Domain]
Measurement Frequency [Domain]
Share capital
Stockholders' Equity Note Disclosure [Text Block]
Components of net periodic benefit cost (income)
Schedule of Net Benefit Costs [Table Text Block]
Line of Credit Facility [Table]
Line of Credit Facility [Table]
Operating Loss Carryforwards [Table]
Operating Loss Carryforwards [Table]
Schedule of Multiemployer Plans [Table]
Multiemployer Plan [Table]
Foreign Currency Derivatives [Abstract]
Foreign Currency Derivatives [Abstract]
Actual plan asset allocation
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage
Tax benefit recognized in income
Share-Based Payment Arrangement, Expense, Tax Benefit
Common shares in Share Trusts (in shares)
Common Stock, Shares Held in Employee Trust, Shares
Repurchase of common shares (in shares)
Number of common shares repurchased (in shares)
Stock Repurchased and Retired During Period, Shares
Weighted-average exchange rate
Derivative, Average Forward Exchange Rate
Resource And Royalties, Commodity Swaps [Member]
Resource And Royalties, Commodity Swaps [Member]
Resource And Royalties, Commodity Swaps
Accounts receivable
Increase (Decrease) in Accounts Receivable
Schedule of Defined Benefit Plans Disclosures [Table]
Schedule of Defined Benefit Plans Disclosures [Table]
Infrastructure [Member]
Private Debt and Infrastructure [Member]
Investments in trust units, participations in private infrastructure funds and public debt and equity securities of infrastructure and utility companies.
Reconciliation for unrecognized tax benefits for domestic and foreign tax positions
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]
Class of Treasury Stock [Table]
Class of Treasury Stock [Table]
Roll forward of outstanding nonvested stock options
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Other Revenues [Member]
Product and Service, Other [Member]
Subsequent events
Subsequent Event [Line Items]
Private Debt, Specialty Portfolio Strategy [Member]
Private Debt, Specialty Portfolio Strategy [Member]
Private Debt, Specialty Portfolio Strategy
Repayment of credit facility
Repayments of Lines of Credit
Weighted-average assumptions used in accounting for pensions and other postretirement benefits
Defined Benefit Plan, Assumptions [Table Text Block]
Personal Injury and Other Claims Provision [Member]
Personal Injury and Other Claims Provision [Member]
This element reflects the current estimated ultimate cost of settling claims relating to workers compensation, personal injury, legal and other claims that have occurred on or before the balance sheet date.
Awards Granted In 2020 and Onwards [Member]
Awards Granted In 2020 And Onwards [Member]
Awards Granted In 2020 And Onwards
Transaction costs, previously capitalized
Business Acquisition, Transaction Costs, Previously Capitalized
Business Acquisition, Transaction Costs, Previously Capitalized
Segmented information
Segment Reporting Disclosure [Text Block]
Schedule of intangible assets, goodwill and other assets by major class
Schedule of Intangible Assets and Goodwill [Table Text Block]
Previously Reported [Member]
Previously Reported [Member]
Settlement loss arising during the year, income tax recovery (expense)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax
Total net deferred income tax liability
Deferred Tax Liabilities, Net
Loss Contingency [Abstract]
Loss Contingency [Abstract]
Liabilities and shareholders' equity
Liabilities and Equity [Abstract]
Income tax recovery, CARES Act
Income Tax Recovery, CARES Act
Income Tax Recovery, CARES Act
Fair Value, Recurring and Nonrecurring [Table]
Fair Value, Recurring and Nonrecurring [Table]
Weighted-average number of shares
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Foreign exchange loss on translation of net investment in foreign operations, before tax
Other Comprehensive Income, Foreign Currency Gain (Loss) on Translation of Net Investment in Foreign Operations, Before Reclassification and Tax
Amount before tax and reclassification adjustments of gain (loss) on foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity.
Total lease liabilities
Lease Liability
Lease Liability
Income Tax Authority [Axis]
Income Tax Authority [Axis]
Canadian National series, 2.25% 10-year notes [Member]
CNR 2022 Notes [Member]
This element includes10-year notes payable due 2022.
Options outstanding
Options Outstanding [Abstract]
PSU-TSR [Member]
Performance Share Unit - TSR [Member]
Performance Share Unit - TSR
Accumulated Depreciation
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, Accumulated Depreciation and Amortization
Transaction-related costs, gross
Business Acquisition, Transaction Costs, Gross
Business Acquisition, Transaction Costs, Gross
Company's additional grant percentage of elected amount
Share Based Compensation Arrangement By Share Based Payment Award Additional Awards Granted Percentage
Percentage of additional units granted by Company based on the amount elected by participant.
Basic (in shares)
Weighted-average basic shares outstanding (in shares)
Weighted Average Number of Shares Outstanding, Basic
Beginning of year
End of year
Loss Contingency Accrual
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Policy
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage
Defined Benefit Plan, Funding Status [Axis]
Defined Benefit Plan, Funding Status [Axis]
Common shares in Share Trusts [Member]
Trust for Benefit of Employees [Member]
Notional amount
Derivative, Notional Amount
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment [Line Items]
Net income by geographic areas
Information By Geographic Area, Net Income [Table Text Block]
Tabular disclosure of net income by geographic areas attributed to the entity's country of domicile and to foreign countries.
Corporate [Member]
Corporate Bond Securities [Member]
Anticipated environmental liability disbursement time frame
Site Contingency, Time Frame of Disbursements
Rate to determine interest cost
Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Interest Rate
The interest rate used to adjust for the time value of money.
Schedule of Long-term Debt Instruments [Table]
Schedule of Long-Term Debt Instruments [Table]
Leases
Lessee, Leases [Policy Text Block]
Level 3 [Member]
Fair Value, Inputs, Level 3 [Member]
Number of options exercisable (in shares)
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable
Stock-based compensation
Share-Based Payment Arrangement [Text Block]
Disclosures of stock-based compensation expense and related tax benefit recognized in income
Share-Based Payment Arrangement, Cost by Plan [Table Text Block]
Foreign currency changes
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)
Provincial and foreign taxes
Income Tax Reconciliation Provincial and Other Taxes
The portion of the difference, between total income tax expense (benefit) as reported in the Income Statement for the period and the expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to provincial and foreign federal, state and local income tax expense (benefit).
Amortization of net actuarial loss, net of tax
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax
Number of common shares (in shares)
Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Purchased For Award, Employer Match
Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Purchased For Award, Employer Match
Kansas City Southern [Member]
Kansas City Southern [Member]
Kansas City Southern
Loss on derivative instruments, net, pretax
Loss on Derivative Instruments, Pretax
Accruals and other
Loss Contingency Accrual, Provision
Award Date [Axis]
Award Date [Axis]
Term of issuance
Term of issuance
Debt Instrument, Term
Significant components of deferred income tax assets and liabilities
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]
Commercial paper, maximum borrowing capacity
Commercial Paper Borrowing Program
Maximum borrowing capacity that the Company is enabling to issue under the commercial paper program.
Guarantor Obligations, Nature [Axis]
Guarantor Obligations, Nature [Axis]
Actuarial gain for increase in discount rate
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) For Change In Discount Rate
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) For Change In Discount Rate
Company contributions (in dollars per share)
Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Contributions, Weighted Average Grant Date Fair Value
Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Contributions, Weighted Average Grant Date Fair Value
Land [Member]
Land [Member]
Dilutive effect of stock-based compensation (in shares)
Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements
Schedule of common stock outstanding roll forward
Schedule of Common Stock Outstanding Roll Forward [Table Text Block]
Disposal Group Name [Domain]
Disposal Group Name [Domain]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Acquisitions, net of cash acquired
Payments to Acquire Businesses, Net of Cash Acquired
Benefit payments, settlements and transfers
Benefit Payments And Transfers
The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets.
Equipment Loan, Non-Revolving Credit Facility [Member]
Equipment Loan, Non-Revolving Credit Facility [Member]
Equipment Loan, Non-Revolving Credit Facility
Level 2 [Member]
Fair Value, Inputs, Level 2 [Member]
Canadian National series, 4.50% 30-year notes [Member]
CNR 2043 Notes [Member]
This element includes 30-year notes payable due 2043
Current Fiscal Year End Date
Current Fiscal Year End Date
Assets held for sale
Disposal Group, Including Discontinued Operation, Assets
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets [Line Items]
Revolving Credit Facility, Tranche Two [Member]
Revolving Credit Facility Tranche Two [Member]
Revolving Credit Facility Tranche for $880 Million maturing on May 5, 2021
Other income (loss)
Other Nonoperating Income and Expense [Text Block]
Domestic
Deferred Tax Assets Liabilities Domestic Net
For entities that net deferred tax assets and tax liabilities, represents the unclassified net amount of deferred tax assets and liabilities as of the balance sheet date for Canadian or domestic operations, which result from applying the applicable enacted tax rate to net temporary differences and carryforwards pertaining to assets or liabilities.
Currency risk percentage exposure
Defined Benefit Plan Currency Risk Percentage Exposure
Percentage of plan assets denominated in foreign currency.
Schedule of Revenues from External Customers and Long-Lived Assets [Table]
Schedule of Revenues from External Customers and Long-Lived Assets [Table]
Plan participants' contributions
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant
Concentration Risk Type [Axis]
Concentration Risk Type [Axis]
Total current liabilities
Liabilities, Current
Cost
Finance Lease, Right-of-Use Asset, before Accumulated Amortization
Accounts receivable
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]
Customer Concentration Risk [Member]
Customer Concentration Risk [Member]
PSU-TSR [Member]
Performance Share Unit Total Shareholder Return [Member]
Performance Share Unit award based on total shareholder return.
Tax information on a domestic and foreign basis
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Prior service credit arising during the year, income tax recovery (expense)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Tax
Unrecognized tax benefits that would impact effective tax rate
Unrecognized Tax Benefits that Would Impact Effective Tax Rate
Other Employee Benefit Liabilities and Workers' Compensation [Member]
Performance Guarantee Related to Workers' Compensation and Other Employee Benefits [Member]
Represents the maximum potential liability under guarantees (letter of credit) for workers' compensation and other employee benefits programs.
Remaining performance obligation
Revenue, Remaining Performance Obligation, Amount
Stock option award expiration term
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period
Floor of exercise price range (in dollars per share)
Share-Based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit
Income tax adjustments due to rate enactments and tax law changes
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount
Income Tax Authority [Domain]
Income Tax Authority [Domain]
Purchase of common shares by Share Trusts
Proceeds from (Payments for) Other Financing Activities
Share-based Payment Arrangement, Option, Exercise Price Range [Table]
Share-Based Payment Arrangement, Option, Exercise Price Range [Table]
Other Award Type [Axis]
Other Award Type [Axis]
Information by specific award type pertaining to equity-based compensation.
Extension term
Accounts Receivable Securitization, Extension Term
Accounts Receivable Securitization, Extension Term
Finance leases
Finance Lease, Weighted Average Remaining Lease Term
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Abstract]
Other - Operating liabilities, at cost [Member]
Operating Liabilities At Cost [Member]
Operating liabilities required to administer the Trusts' investment assets and the plans' benefit and funding activities valued at cost.
Credit Facility [Axis]
Credit Facility [Axis]
Bonds and mortgages [Member]
Bonds Mortgages [Member]
This category includes bonds (information about long-term debt securities that are issued by either a domestic or foreign corporate business entity with a date certain promise of repayment and a return to the holder for the time value of money (for example, variable or fixed interest, original issue discount)); mortgages (a loan to finance the purchase of real estate where the lender has a lien on the property as collateral for the loan).
Long-term debt
Total long-term debt
Long-Term Debt and Lease Obligation
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract]
US Dollar-Denominated [Member]
United States of America, Dollars
Period of time options are generally not exercisable
Share-based Compensation Arrangement by Share-based Payment Award, Option, Not Excercisable Term
Number of months after the date of the grant in which options are generally not exercisable.
Employer's contributions
Defined Contribution Plan, Employer Discretionary Contribution Amount
Equity [Abstract]
Equity [Abstract]
Subsequent Event [Table]
Subsequent Event [Table]
Units vested during the year (in shares)
Vested (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period
Forest Products [Member]
Timber [Member]
Environmental provisions
Current portion - End of year
Accrued Environmental Loss Contingencies, Current
Finance lease liability [Member]
Finance Lease Liability [Member]
Finance Lease Liability [Member]
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Risk management
Derivatives, Fair Value [Line Items]
Long-lived assets by geographic areas
Long-Lived Assets by Geographic Areas [Table Text Block]
Units outstanding at beginning of period (in shares)
Units outstanding at end of period (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding, Number
Schedule of Short-term Debt [Table]
Schedule of Short-Term Debt [Table]
Ballast installation, minimum level of activity to be capitalized
Ballast installation, minimum level of activity to be capitalized
Describes the minimum level of activity of costs an entity capitalizes as part of property, plant and equipment, including the costs incurred for repairs and maintenance activities.
Weighted-average grant date fair value at beginning of period (in dollars per share)
Weighted-average grant date fair value at end of period (in dollars per share)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Grant Date Fair Value
The weighted average fair value at grant date for outstanding equity-based awards other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).
Freight [Member]
Freight [Member]
Maturity of guarantee instruments
Guarantor Obligations, Term
Maximum potential liability under guarantees
Guarantor Obligations, Maximum Exposure, Undiscounted
Net actuarial gain (loss)
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax
Reconciliation of income tax expense
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
Foreign exchange
Foreign exchange
The Increase or (Decrease) in the loss contingencies during the reporting period related to currency translations.
Net increase (decrease) in cash, cash equivalents, restricted cash, and restricted cash equivalents
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect
Entity Central Index Key
Entity Central Index Key
Antidilutive Securities, Name [Domain]
Antidilutive Securities, Name [Domain]
U.S. Equities [Member]
Us Equities [Member]
This category includes information about ownership interests or the right to acquire ownership interests in U.S. corporations and other legal entities which ownership interest is represented by shares of common or preferred stock (which is neither mandatorily redeemable no redeemable at the option of the holder), convertible securities, stock rights, or stock warrants.
Deferred tax recovery
Unrecognized Tax Benefits, Decrease Resulting from Re-Estimate Of Income Tax Examination
Unrecognized Tax Benefits, Decrease Resulting from Re-Estimate Of Income Tax Examination
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]
Stock price (in dollars per share)
Stock Price at Grant Date of Share-based Payment Awards
The stock price at grant date of equity settled stock-based compensation awards.
Accounts receivable securitization
Transfers and Servicing of Financial Assets, Transfers of Financial Assets, Policy [Policy Text Block]
Other Award Type [Axis]
Share-based Compensation Arrangements by Share-based Payment Award Type [Axis]
Stock-based compensation awards other equity awards.
Assets
Assets [Abstract]
Other current assets
Increase (Decrease) in Other Current Assets
Other operating activities, net
Increase (Decrease) in Other Operating Assets and Liabilities, Net
Restated [Member]
Revision of Prior Period, Adjustment [Member]
Maturity Greater than 90 Days [Member]
Maturity Greater than 90 Days [Member]
Government Assistance [Table]
Government Assistance [Table]
Change in accounting policy for determining net periodic pension cost (income)
Pension and Other Postretirement Plans, Policy [Policy Text Block]
PSU-ROIC [Member]
Performance Share Unit ROIC [Member]
Performance Share Unit award based on return on invested capital.
Total amount recognized
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position
Net gain (loss) on foreign currency translation
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax
Earnings per share
Earnings Per Share, Policy [Policy Text Block]
2023
Long-Term Debt, Maturity, Year One
Number of participants holding shares
Share Based Compensation Arrangement By Share Based Payment Award Employee Participants Number
The number of employees participating in the plan and holding shares at the balance sheet date.
Weighted average grant date fair value per share of nonvested options granted during the period (in dollars per share)
Weighted-average grant date fair value (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value
Other liabilities and deferred credits
Total other liabilities and deferred credits
Other Liabilities, Noncurrent
Anticipated environmental liability disbursement time frame (in years)
Site Contingency, Time Frame Of Disbursements, Term
Site Contingency, Time Frame Of Disbursements, Term
Property additions
Property additions
Payments to Acquire Property, Plant, and Equipment
Private Equity Funds, Specialty Portfolio Strategy [Member]
Private Equity Funds, Specialty Portfolio Strategy [Member]
Private Equity Funds, Specialty Portfolio Strategy
Derivative term
Derivative, Term of Contract
Long-term purchase commitment
Long-Term Purchase Commitment, Amount
LTD other disclosures
Long-Term Debt, Other Disclosure [Abstract]
Projected benefit obligation at beginning of year
Projected benefit obligation at end of year
Defined Benefit Plan, Benefit Obligation
2028 & thereafter
Finance Lease, Liability, to be Paid, after Year Five
Net interest expense deduction carryforward
Operating Loss Carryforwards, Net Interest Expense Deduction
Operating Loss Carryforwards, Net Interest Expense Deduction
Earnings per share reconciliation
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Interest rate
Line of Credit Facility, Interest Rate at Period End
Operating lease
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability
Emerging Market Debt, Swap [Member]
Emerging Market Debt, Swap [Member]
Emerging Market Debt, Swap [Member]
Actual plan asset allocation
Defined Benefit Plan, Plan Liabilities, Actual Allocation, Percentage
Defined Benefit Plan, Plan Liabilities, Actual Allocation, Percentage
Other postretirement benefits [Member]
Other Postretirement Benefits Plan [Member]
Income tax expense reconciliation
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Deferred credits and other
Deferred Credits and Other Liabilities, Noncurrent
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Rate of compensation increase
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase
Total lease payments
Lessee, Operating Lease, Liability, to be Paid
Rail and related track material, minimum level of activity to be capitalized
Rail and related track material, minimum level of activity to be capitalized
Describes the minimum level of activity of costs an entity capitalizes as part of property, plant and equipment, including the costs incurred for repairs and maintenance activities.
Government Assistance, Type [Domain]
Government Assistance, Type [Domain]
Bond, Options [Member]
Bond, Options [Member]
Bond, Options
Decrease for:
Decreases [Abstract]
Lease liabilities
Deferred Tax Assets, Lease Liability
Deferred Tax Assets, Lease Liability
Actuarial gain (loss) arising during the year, income tax recovery (expense)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax
2024
Long-Term Debt, Maturity, Year Two
Reconciliation for unrecognized tax benefits on the Company's domestic and foreign tax positions
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Amendments
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment
Long Lived Assets Held-for-sale, Name [Domain]
Long-Lived Assets Held-for-sale, Name [Domain]
Maximum borrowing capacity
Bilateral letter of credit facilities, total available amount
Line of Credit Facility, Maximum Borrowing Capacity
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Abstract]
Current portion of long-term debt
Less: Current portion of long-term debt
Long-Term Debt and Lease Obligation, Current
Properties
Deferred Tax Liabilities, Property, Plant and Equipment
Period in years over which realized and unrealized gains/losses and appreciation/depreciation in the value of the investments are recognized based on the companies election to use market related value
Defined Benefit Plan Recognition Period For Changes In Value Of Investments
Period of time over which realized and unrealized gains/losses and appreciation/depreciation in the value of the investments are recognized.
Range of Exercise Prices 2 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range 2 [Member]
One range (Range 2) in a series of customized ranges of exercise prices for the purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards for this range.
Investing activities
Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract]
Other income (loss)
Schedule of Other Nonoperating Income (Expense) [Table Text Block]
Other investing activities, net
Payments for (Proceeds from) Other Investing Activities
Public Equity Investment, Specialty Portfolio Strategy [Member]
Public Equity Investment, Specialty Portfolio Strategy [Member]
Public Equity Investment, Specialty Portfolio Strategy
Statistical Measurement [Domain]
Statistical Measurement [Domain]
Proceeds from debt issuance
Proceeds from Issuance of Debt
Personal injury and other claims provisions
Personal Injury And Other Claims Provisions Current
This element reflects the current estimated ultimate cost of settling claims relating to workers compensation, personal injury, legal and other claims that have occurred on or before the balance sheet date.
Weighted-average grant date fair value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Weighted Average Grant Date Fair Value [Abstract]
Depreciation rate
Annual Rate of Depreciation
The percent by which an asset loses value on an annual basis.
Share-based Payment Arrangement [Abstract]
Share-Based Payment Arrangement [Abstract]
Other Award Type [Domain]
Share Based Compensation Arrangements By Share Based Payment Award Type [Domain]
Share Based Compensation Arrangements By Share Based Payment Award Type [Domain]
Stock-based compensation other equity settled award type.
Net periodic benefit cost (income)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)
Repayment of debt
Repayments of Debt
Finance leases included in properties
Schedule Of Lessee, Finance Lease, Right-Of-Use Asset [Table Text Block]
Schedule Of Lessee, Finance Lease, Right-Of-Use Asset [Table Text Block]
Properties
Net
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Segmented Information [Abstract]
Segment Reporting Information, Additional Information [Abstract]
Net income
Net income
Net Income (Loss) Attributable to Parent
Leases
Lessee, Finance Leases [Text Block]
Other [Member]
Other Plan Assets [Member]
Operating assets and operating liabilities required to administer the Trusts' investment assets and the plans' benefit and funding activities valued at cost.
Cumulative Effect, Period of Adoption [Axis]
Cumulative Effect, Period of Adoption [Axis]
Schedule of debt maturities
Schedule of Maturities of Long-Term Debt [Table Text Block]
Amortization of prior service cost (credit)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)
Subsequent Event Type [Axis]
Subsequent Event Type [Axis]
Rate of compensation increase
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase
Canadian National series, 6.25% 30-year notes [Member]
CNR 2034 Notes [Member]
This element includes 30-year notes payable due 2034.
Gross accounts receivable
Accounts Receivable, before Allowance for Credit Loss, Current
Scenario [Axis]
Scenario [Axis]
Performance vesting factor
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage
Leases
Lessee, Operating Leases [Text Block]
Coal [Member]
Coal [Member]
Plan Name [Axis]
Plan Name [Axis]
Number of retirees covered
Multiemployer Plan Number Of Retirees Covered
Number of retirees covered under multiemployer plan.
Multi Strategy Funds [Member]
Multi Strategy Funds [Member]
A portfolio of units of externally managed hedge funds investing mainly in multi-strategy funds.
Material and supplies
Inventory Supplies, Policy [Policy Text Block]
Total debt
Long-Term Debt and Lease Obligation, Including Current Maturities
Finite-Lived Intangible Assets, Net [Abstract]
Finite-Lived Intangible Assets, Net [Abstract]
Derivative Instrument [Axis]
Derivative Instrument [Axis]
Number of operating segments
Number of Operating Segments
Maximum percentage of equity investments allocated to an industry sector (in hundredths)
Defined Benefit Plan Maximum Percentage Of Equity Investments Allocated To Industry Sector
Maximum percentage of equity investments allocated to an industry sector during the period.
Environmental provisions
Accrued Environmental Loss Contingencies, Noncurrent
Statement of Cash Flows [Abstract]
Statement of Cash Flows [Abstract]
Level 1 [Member]
Fair Value, Inputs, Level 1 [Member]
Unrealized foreign exchange gains
Deferred Tax Liabilities, Unrealized Currency Transaction Gains
Prior service credit (cost)
Prior service credit (cost)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax
Various Other Currencies [Member]
Foreign Currency Risk Exposure to Other Currencies [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities
Net Cash Provided by (Used in) Operating Activities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other Liabilities [Member]
Equipment Under Leases and Other [Member]
Represents the maximum potential liability under guarantees (letter of credit) for equipment leases and other programs.
Income tax expense resulting from:
Income Tax Expense Recovery Resulting From [Abstract]
Canada, U.S. and supranational [Member]
Canada And Supranational [Member]
This category includes information about long-term debt securities that are issued by international governments and the Canadian federal government with a date certain promise of repayment and a return to the holder for the time value of money (for example, variable or fixed interest, original issue discount).
Other components of net periodic benefit income
Total Other components of net periodic benefit cost (income)
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component
Forfeited/Cancelled (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period
Receivables [Abstract]
Receivables [Abstract]
Schedule of US dollar-denominated debt
Schedule of US Dollar-Denominated Debt [Table Text Block]
Tabular disclosure of US dollar denominated debt.
Other Equipment Loan [Member]
Other Equipment Loan [Member]
Other Equipment Loan
Geographical [Axis]
Geographical [Axis]
Amortization of gain on treasury lock, before tax
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax
Pension and other postretirement benefits
Noncurrent liabilities - Pension and other postretirement benefits
Liability, Defined Benefit Plan, Noncurrent
Accounting Changes and Error Corrections [Abstract]
Investment-related liabilities [Member]
Investment Related Liabilities [Member]
Investment Related Liabilities [Member]
Properties including finance leases
Property, Plant and Equipment [Table Text Block]
Postretirement Health Coverage [Member]
Postretirement Health Coverage [Member]
Weighted-average remaining lease term (years)
Weighted Average Remaining Lease Term [Abstract]
Weighted Average Remaining Lease Term [Abstract]
Adjustments to reflect tax treaties and other arrangements
Tax Adjustments For Tax Treaties
Concentration Risk Benchmark [Domain]
Concentration Risk Benchmark [Domain]
Roll forward of nonvested PSUs
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
2025
Defined Benefit Plan, Expected Future Benefit Payment, Year Three
Additional income, pre-tax
Business Combination, Income Pre-Tax
Business Combination, Income Pre-Tax
Product and Service [Domain]
Product and Service [Domain]
Operating activities
Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract]
Tax positions related to prior years
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions
Schedule of allocation of plan assets
Schedule of Allocation of Plan Assets [Table Text Block]
2023
Lessee, Operating Lease, Liability, to be Paid, Year One
Petroleum And Chemicals [Member]
Petroleum And Chemicals [Member]
Petroleum And Chemicals [Member]
European Currencies [Member]
Foreign Currency Risk Exposure to European Currencies [Member]
Decrease in service cost
Defined Benefit Plan, Increase (Decrease) In Service Cost
Defined Benefit Plan, Increase (Decrease) In Service Cost
2025
Long-Term Debt, Maturity, Year Three
Regulatory Compliance [Abstract]
Regulatory Compliance [Abstract]
May incur significant capital and operating costs associated with environmental regulatory compliance and clean-up requirements in its railroad operations and relating to its past and present ownership, operation and control of real property.
Deferred income tax liabilities
Components of Deferred Tax Liabilities [Abstract]
Financial instruments
Financial Instruments Disclosure [Text Block]
Valuation method used in calculating the fair value of PSUs
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Method Used
Revenue Benchmark [Member]
Revenue Benchmark [Member]
Subsequent Event [Member]
Subsequent Event [Member]
Document Period End Date
Document Period End Date
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Share-Based Payment Arrangement, Option, Exercise Price Range [Line Items]
Other current assets
Other Current Assets [Text Block]
Amortization of prior service cost (credit), before tax
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax
Components of accumulated other comprehensive loss
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
Total assets
Assets
Right-of-Way Access [Member]
Right-of-Way Access [Member]
Earnings per share
Earnings per share:
Earnings Per Share [Abstract]
Settlement of equity settled awards (in shares)
Number of common shares (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Shares Disbursed for Award
Number of shares settled by Share trusts
Assumptions
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Weighted-average price per share (in dollars per share)
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Settled
Weighted-average price per share disbursed Share Trusts.
Repayment
Repayments of Commercial Paper
Performance Share Units [Member]
Performance Shares [Member]
Antidilutive Securities [Axis]
Antidilutive Securities [Axis]
Accounts payable and other
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]
Number of depreciable asset classes
Number of depreciable asset classes
Number of depreciable asset classes.
Weighted average exercise price of options exercised (in dollars per share)
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price
2027
Lessee, Operating Lease, Liability, to be Paid, Year Five
Payroll-related accruals
Employee-related Liabilities, Current
Earnings per share
Earnings Per Share [Text Block]
Bond Forwards [Member]
Bond Forwards [Member]
Bond Forwards
Other
Deferred Tax Liabilities, Other
Share Trusts
Employee Trust [Abstract]
Postretirement benefits amortization of cumulative net actuarial gains and losses excess threshold
Postretirement Other Than Pension Amortization Threshold Gain Loss
Other postretirement benefits amortization of cumulative net actuarial gains and losses percentage in excess of the projected benefit obligation at the beginning of the year, over the expected average remaining service life of the employee group covered by the plan.
Cash and cash equivalents
Cash and Cash Equivalents, Policy [Policy Text Block]
Grant date fair value of options vested
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested in Period, Fair Value
Award Type [Domain]
Award Type [Domain]
Settled (in shares)
Share Based Compensation Arrangement By Share Based Payment Award Non Option Equity Instruments Settled
The number of units settled during the period.
Income taxes receivable
Income Taxes Receivable, Current
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Canadian National series, 6.90% 30-year notes [Member]
CNR 2028 Notes [Member]
This element includes 30-year notes payable due 2028.
Financing activities
Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract]
Discounted debt
Discounted debt
Represents the amount of discounted debt.
Goodwill
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]
Mortgages [Member]
Mortgages [Member]
Software Development [Member]
Software Development [Member]
Issuances and repayments of commercial paper
Proceeds from (Repayments of) Commercial Paper [Abstract]
Units excluded from the calculation as their inclusion would not have a dilutive effect
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Abstract]
Antidilutive Securities Excluded From Computation Of Earnings Per Share
Foreign currency translation adjustments [Member]
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Environmental operating expenses
Environmental Remediation Expense
Derivative instruments [Member]
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Share settlements by Share Trusts
Stock Settled During Period, value
Amount of common shares settled by Share Trusts (value)
Operating expenses
Operating Expenses [Abstract]
Foreign currency changes
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)
Years 2028 to 2032
Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years
Restricted cash and cash equivalents
Restricted cash and cash equivalents, end of year
Restricted Cash and Cash Equivalents, Current
Statement of Financial Position [Abstract]
Statement of Financial Position [Abstract]
Canadian National series, 7.38% 30-year debentures [Member]
CNR 2031 Debentures [Member]
This element includes 30-year debentures due 2031.
Canadian National series, 6.38% 30-year debentures [Member]
CNR 2037 Debentures [Member]
This element includes 30-year debentures due 2037.
Fair value of outstanding foreign exchange forward contracts
Unrealized Gain (Loss) on Derivatives
Issued and outstanding common shares
Shares Granted or Issued, Share-Based Payment Arrangement [Abstract]
Maximum cash proceeds from sale of accounts receivable to unrelated trust
Securitization Program Maximum Cash Proceeds Limit
Maximum dollar amount of cash proceeds for undivided co-ownership interest in a revolving pool of accounts receivables company expects in sale.
Bridge financing and other fees
Debt Issuance Costs, Net
Pension Plan [Member]
Pension Plan [Member]
Closing stock price (in dollars per share)
Share Price
Net operating loss carryforwards
Operating Loss Carryforwards
Change in Accounting Principle, Type [Axis]
Change in Accounting Principle, Type [Axis]
Transaction costs
Business Acquisition, Transaction Costs
Trade payables
Accounts Payable, Trade, Current
Contract liabilities
Contract with Customer, Liability, Noncurrent
Stock-based compensation liability
Deferred Compensation Share-Based Arrangements, Liability, Classified, Noncurrent
Canada [Member]
CANADA
Tax positions related to prior years
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions
NAV [Member]
Fair Value Measured at Net Asset Value Per Share [Member]
Disposal Group Classification [Axis]
Disposal Group Classification [Axis]
BC Rail series, non-interest bearing 90-year subordinated notes [Member]
BCR 2094 Subordinted Notes [Member]
This element includes non-interest bearing 90-year subordinated notes due 2094.
Actual return relating to assets still held at the reporting date
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held
Pension asset
Deferred Tax Liabilities Prepaid Pension Costs
The amount as of the balance sheet date of the estimated future tax effects attributable to the difference between the tax basis of pension liabilities funded in advance and the basis of a prepaid pension asset determined in accordance with generally accepted accounting principles. The difference in basis of such costs will increase future taxable income when such basis difference reverses. Prepaid pension costs represented the cumulative employer's contributions in excess of net pension cost recognized, before the adoption of the recognition provisions of FAS 158. Under FAS 158, prepaid pension costs are no longer recognized in the statement of financial position.
Intangible assets, goodwill and other
Total intangible assets, goodwill and other
Intangible Assets, Net (Including Goodwill) And Other
Intangible Assets, Net (Including Goodwill) And Other
Freight [Member]
Cargo and Freight [Member]
Subsequent Events [Abstract]
Subsequent Events [Abstract]
Grant date fair value
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Fair Value
The total grant date fair value of equity settled awards determined by using valuation models.
Reconciliation of the fair value of investments categorized as Level 3
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets [Table Text Block]
Units granted (in shares)
Granted (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Granted
Increase (decrease) to personal injury and other claims provision pursuant to the results of external actuarial studies
Net reductions to personal injury and other claims provision pursuant to the results of external actuarial studies
The increase (decrease) in the loss contingency accrual in the period from revisions in estimates to existing obligations.
Interest paid
Interest Paid, Excluding Capitalized Interest, Operating Activities
2025
Lessee, Operating Lease, Liability, to be Paid, Year Three
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Disclosure [Line Items]
Line of credit facility, draws during period
Line of Credit Facility, Maximum Amount Outstanding During Period
Future taxable income to realize deferred income tax assets
Future taxable income to realize deferred income tax assets
Change in commercial paper, net
Change in commercial paper, net
Proceeds from (Repayments of) Commercial Paper
Pension and other postretirement benefit plans [Member]
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Fair value of plan assets
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets
Concentration Risk Type [Domain]
Concentration Risk Type [Domain]
Total shareholders' equity
Shareholders' equity, beginning balance
Shareholders' equity, ending balance
Stockholders' Equity Attributable to Parent
Canadian National series, 2.80% 10-year notes [Member]
Cnr 2025 Notes
Canadian National series, 2.80% 10-year notes
Finance lease
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability
Weighted-average grant date fair value of units forfeited in period (in dollars per share)
Weighted-average grant date fair value of units forfeited in period (in dollars per share)
Forfeited (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value
Accounts receivable securitization borrowings
Beginning of year
End of year
Accounts Receivable Securitization Borrowings
Accounts Receivable Securitization Borrowings
Canadian National series, 3.85% 10-year notes [Member]
CNR 2032 Notes [Member]
CNR 2032 Notes
Line of Credit Facility [Line Items]
Line of Credit Facility [Line Items]
Expected return on plan asset assumption to be used in future year (in hundredths)
Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets Future Year
An assumption as to the long-term rate of return on plan assets to be used in the future year reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.
Other
Deferred Tax Assets, Other
Infrastructure, Foreign Exchange Forwards [Member]
Infrastructure, Foreign Exchange Forwards [Member]
Infrastructure, Foreign Exchange Forwards
Award Date [Domain]
Award Date [Domain]
2027
Long-Term Debt, Maturity, Year Five
Retained earnings [Member]
Retained Earnings [Member]
Unrecognized compensation cost related to nonvested options outstanding
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount
Bilateral Letter Of Credit Facilities [Member]
Bilateral Letter Of Credit Facilities [Member]
Bilateral Letter Of Credit Facilities [Member]
Dividends
Dividends, Common Stock, Cash
Total lease cost
Lease, Cost
Common shares [Member]
Common Stock [Member]
Schedule of lease costs and additional information
Lease, Cost [Table Text Block]
Remaining common stock authorized for future issuances under plan (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant
Statement [Table]
Statement [Table]
Weighted-average grant date fair value of units vested in period (in dollars per share)
Vested (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value
Interest rate
Debt Instrument, Interest Rate, Effective Percentage
Intangible assets amortization method
Finite-Lived Intangible Assets, Amortization Method
llinois Central series, 7.70% 100-year debentures [Member]
Illinois Central Series Seven Point Seventy Percent 100 Year Debentures Maturing 2096 [Member]
This element includes Illinois Central 100-year debenture
Operating lease liabilities
Operating leases
Operating Lease, Liability, Noncurrent
Accruals and other
Accrual for Environmental Loss Contingencies, Charges to Expense for New Losses
Statistical Measurement [Axis]
Statistical Measurement [Axis]
Merger termination fee
Business Combination, Merger Termination Fee
Business Combination, Merger Termination Fee
Disposal Group Name [Axis]
Disposal Group Name [Axis]
International Equities [Member]
International Equities [Member]
This category includes information about ownership interests or the right to acquire ownership interests in International corporations and other legal entities which ownership interest is represented by shares of common or preferred stock (which is neither mandatorily redeemable no redeemable at the option of the holder), convertible securities, stock rights, or stock warrants.
Common shares in Share Trusts
Common Stock Held in Trust
Accounts receivable
Net accounts receivable
Accounts Receivable, after Allowance for Credit Loss, Current
Equity Components [Axis]
Equity Components [Axis]
Amounts recognized in the consolidated balance sheet
Schedule of Amounts Recognized in Balance Sheet [Table Text Block]
Equity Settled Awards [Member]
Equity Settled Awards [Member]
Equity-based compensation that is settled in common shares of the Company.
Non-Revolving Credit Facility [Member]
Non-Revolving Credit Facility [Member]
Non-Revolving Credit Facility [Member]
Other Comprehensive Income (Loss) Before Reclassifications [Abstract]
Other Comprehensive Income (Loss) Before Reclassifications [Abstract]
Share Repurchase Program (02/01/2021 - 01/31/2022) [Member]
Stock Repurchase Program, Period in Force, One [Member]
Period in force, in which shares may be purchased under a stock repurchase plan authorized by an entity's Board of Directors.
Revision of Prior Period [Domain]
Revision of Prior Period [Domain]
Track And Railway Infrastructure [Member]
Track And Railway Infrastructure [Member]
Track And Railway Infrastructure [Member]
Long-term Purchase Commitment, Category of Item Purchased [Domain]
Long-Term Purchase Commitment, Category of Item Purchased [Domain]
Canadian National series, 3.00% 10-year notes [Member]
CNR Two Thousand Twenty-Nine Ten Year Notes [Member]
CNR Two Thousand Twenty-Nine Ten Year Notes [Member]
Statement [Line Items]
Statement [Line Items]
Units nonvested at beginning of period (in shares)
Units nonvested at end of period (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number
Long Lived Assets Held-for-sale [Line Items]
Long-Lived Assets Held-for-sale [Line Items]
Percentage of bonds guaranteed by governments and corporate entities (in hundredths)
Defined Benefit Plan Percentage Of Bonds Held In Short Term Investments That Are Investment Grade Issued By Governments
Percentage of bonds issued or guaranteed by Canadian, U.S. or other governments and were of investment grade.
Total other income (loss)
Nonoperating Income (Expense)
Information for the pension plans with a projected benefit obligation in excess of plan assets
Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets [Table Text Block]
Schedule of Long Lived Assets Held-for-sale [Table]
Schedule of Long-Lived Assets Held-for-sale [Table]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Range of Exercise Prices 1 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range 1 [Member]
One range (Range 1) in a series of customized ranges of exercise prices for the purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards for this range.
Information for the pension plans with an accumulated benefit obligation in excess of plan assets [Abstract]
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Pension income and funding
Pension and Other Postretirement Benefits Expense (Reversal of Expense), Noncash
Operating lease right-of-use assets
Operating leases
Operating Lease, Right-of-Use Asset
Share purchases by Share Trusts
Amount of purchase
Stock Repurchased During Period, Value
Accumulated other comprehensive loss [Member]
AOCI Attributable to Parent [Member]
Expected going concern basis excess (deficit) funded status
Expected Going Concern Defined Benefit Plan Funded Status Of Plan
The expected going concern excess (deficit) funded status is measured as the difference between the fair value of plan assets and the benefit obligation based on an upcoming or future actuarial valuation, for funding purposes. The estimated excess (deficit) is based on current projected results of actuarial funding valuations on a solvency basis. Actuarial valuations for funding purposes are subject to revaluation on an annual basis.
Accumulated other comprehensive loss
Comprehensive Income (Loss) Note [Text Block]
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]
2024
Defined Benefit Plan, Expected Future Benefit Payment, Year Two
Other comprehensive income before income taxes
Other comprehensive income before income taxes
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent
Accounts Receivable Securitization [Roll Forward]
Accounts Receivable Securitization [Roll Forward]
Accounts Receivable Securitization [Roll Forward]
Activity of stock option awards
Share-Based Payment Arrangement, Option, Activity [Table Text Block]
Operating income
Operating Income (Loss)
Other Income, Nonoperating [Abstract]
Other Income, Nonoperating [Abstract]
Recent accounting pronouncements
New Accounting Pronouncements, Policy [Policy Text Block]
State and Local Jurisdiction [Member]
State and Local Jurisdiction [Member]
Pensions
Pension and Other Postretirement Plans, Pensions, Policy [Policy Text Block]
Amortization of net actuarial loss, before tax
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax
Public Equities, Swap [Member]
Public Equities, Swap [Member]
Public Equities, Swap
Canadian National series, 4.00% 50-year notes [Member]
Cnr 2065 Notes [Member]
This element includes 50-year notes payable due 2065.
Adjustments to reconcile net income to net cash provided by operating activities:
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Intangible assets, goodwill and other
Goodwill and Intangible Assets Disclosure [Text Block]
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]
Domestic
Current Federal, State and Local, Tax Expense (Benefit)
Properties
Property, Plant and Equipment, Policy [Policy Text Block]
2026
Lessee, Operating Lease, Liability, to be Paid, Year Four
Income Statement [Abstract]
Income Statement [Abstract]
Stock options granted (in shares)
Granted (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross
Additional paid-in capital [Member]
Additional Paid-in Capital [Member]
Document Fiscal Period Focus
Document Fiscal Period Focus
Intrinsic value of options exercised
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value
Employee injuries, Canada [Member]
Employee injuries, Canada
Information about employee injuries in Canada.
Component of Other Income, Nonoperating [Abstract]
Component of Other Income, Nonoperating [Abstract]
Canadian National series, 2.45% 30-year notes [Member]
CNR Two Thousand Fifty Thirty Year Notes, Thirty Year Notes [Member]
CNR Two Thousand Fifty Thirty Year Notes, Thirty Year Notes
Diluted (in shares)
Weighted-average diluted shares outstanding (in shares)
Weighted Average Number of Shares Outstanding, Diluted
Intangible assets
Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block]
Guarantor Obligations [Line Items]
Guarantor Obligations [Line Items]
Loss Contingency, Nature [Domain]
Loss Contingency, Nature [Domain]
Voluntary Incentive Deferral Plan (VIDP) [Member]
Voluntary Incentive Deferral Plan [Member]
Voluntary Incentive Deferral Plan providing eligible senior management employees the opportunity to elect to receive their annual incentive bonus payment and other eligible incentive payments in deferred share units (DSUs).
Expected term (years)
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term
Schedule of change impacted previously reported amounts
Accounting Standards Update and Change in Accounting Principle [Table Text Block]
Equity investments with readily determinable fair value
Equity Securities, FV-NI
Purchase And Self Construction Properties [Member]
Purchase And Self Construction Of Properties [Member]
Purchase And Self Construction Of Properties
Canadian Dollar [Member]
Foreign Currency Risk Exposure to Canadian Dollar [Member]
Weighted-average grant date fair value of units granted in period (in dollars per share)
Weighted-average grant date fair value (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value
Short-term Debt [Line Items]
Short-Term Debt [Line Items]
Aggregate intrinsic value of options exercisable
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value
Units settled (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Settled in Period
The number of units settled/paid out during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).
Short-term lease cost
Short-Term Lease, Cost
Reconciliation between basic and diluted earnings per share:
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Other
Other Nonoperating Expense
Additional paid-in capital
Additional Paid-In Capital Policy [Policy Text Block]
Additional Paid-In Capital Policy [Policy Text Block]
Approximate amount of unrecognized tax benefits that may be recognised over the next 12 months as a result of settlements and a lapse of the applicable statute of limitations
Decrease in Unrecognized Tax Benefits is Reasonably Possible
Other postretirement benefits liability
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits
Major commitments and contingencies
Commitments and Contingencies Disclosure [Text Block]
Fuel
Fuel Costs
Non-taxable portion of merger termination fee
Effective Income Tax Rate Reconciliation, Non-Taxable Portion Of Merger Termination Fee, Amount
Effective Income Tax Rate Reconciliation, Non-Taxable Portion Of Merger Termination Fee, Amount
Foreign Exchange Forward [Member]
Foreign Exchange Forward [Member]
Issuance of debt
Proceeds from Issuance of Long-Term Debt
Shareholders' equity, beginning balance (in shares)
Shareholders' equity, ending balance (in shares)
Issued common shares (in shares)
Common Stock, Shares, Issued
Investments accounted for under the equity method
Equity Method Investments
Schedule of activity of purchases and settlements by share trusts
Schedule of Activity, Share Trust [Table Text Block]
Tabular disclosure of the information related to the share trusts common share purchase.
Renewal term
Lessee, Lease, Renewal Term
Lessee, Lease, Renewal Term
Gain (loss) on foreign currency
Foreign Currency Transaction Gain (Loss), before Tax
Foreign exchange gain (loss) on translation of net investment in foreign operations, net of tax
Other Comprehensive Income, Foreign Currency Gain (Loss) on Translation of Net Investment in Foreign Operations, Net of Tax
Amount after tax, and before reclassification adjustments of gain (loss) on foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity.
Market-related value, as a percentage
Defined Benefit Plan, Plan Assets, Market-Related Value As A Percentage
Defined Benefit Plan, Plan Assets, Market-Related Value As A Percentage
Transaction-related costs
Business Combination, Acquisition Related Costs
Finance leases
Finance Lease, Liability, Current
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net cash used in investing activities
Net Cash Provided by (Used in) Investing Activities
Debt issued, face amount
Debt Instrument, Face Amount
Comprehensive income
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Liability current carrying value
Guarantor Obligations, Current Carrying Value
Loss (recovery) on assets held for sale
Loss on assets held for sale
Impairment of Long-Lived Assets to be Disposed of
Other
Other Liabilities, Current
Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table]
Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table]
Grant date fair value (in dollars per share)
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Grants In Period, Fair Value Per Share
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Grants In Period, Fair Value Per Share
Range of Exercise Prices 3 [Member]
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range 3 [Member]
One range (Range 3) in a series of customized ranges of exercise prices for the purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards for this range.
Schedule of obligations and funded status
Schedule of Net Funded Status [Table Text Block]
2023
Finance Lease, Liability, to be Paid, Year One
Disaggregation of Revenue [Table]
Disaggregation of Revenue [Table]
Environmental expenditures
Environmental Costs, Policy [Policy Text Block]
Share Purchases by Share Trusts [Abstract]
Share Purchases by Share Trusts [Abstract]
Canadian statutory federal tax rate
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent
Swap [Member]
Swap [Member]
Canadian National series, 2.95% 10-year notes [Member]
CNR 2024 Notes 10 Yr [Member]
This element includes 10 year notes payable due 2024.
Properties including finance leases
Property, Plant and Equipment, Net, Including and Excluding Capital Leased Asset [Abstract]
Funded [Member]
Defined Benefit Plan, Funded Plan [Member]
Options outstanding at beginning of period (in shares)
Options outstanding at end of period (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number
Subsequent event, description
Subsequent Event, Description
Provinces of Canada and Municipalities [Member]
Provinces of Canada and Municipalities [Member]
This category includes information about long-term debt securities that are issued by provincial governments and municipalities in Canada with a date certain promise of repayment and a return to the holder for the time value of money (for example, variable or fixed interest, original issue discount).
Schedule of Stock by Class [Table]
Schedule of Stock by Class [Table]
Renewal option, amount
Lessee, Operating Lease, Renewal Option, Amount
Lessee, Operating Lease, Renewal Option, Amount
Actuarial gain (loss) arising during the year, net of tax
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax
Foreign exchange gain
Business Combination, Foreign Exchange Gain (Loss)
Business Combination, Foreign Exchange Gain (Loss)
2024
Finance Lease, Liability, to be Paid, Year Two
Basis of presentation
Basis of Accounting, Policy [Policy Text Block]
Effect of foreign exchange fluctuations on cash, cash equivalents, restricted cash, and restricted cash equivalents
Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations
Expected solvency basis excess (deficit) funded status
Expected Defined Benefit Plan Funded Status Of Plan
The expected excess (deficit) funded status is measured as the difference between the fair value of plan assets and the benefit obligation based on an upcoming or future actuarial valuation, for funding purposes. The estimated excess (deficit) is based on current projected results of actuarial funding valuations on a solvency basis. Actuarial valuations for funding purposes are subject to revaluation on an annual basis.
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]
Units forfeited in period (in shares)
Forfeited (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period
Commodity Fund [Member]
Commodity Fund [Member]
Commodity Fund
Total
Debt, excluding finance leases, carrying amount
Long-Term Debt
Other income (loss)
Other Nonoperating Income (Expense)
Balance Sheet Location [Axis]
Balance Sheet Location [Axis]
Guarantor Obligations, Nature [Domain]
Guarantor Obligations, Nature [Domain]
Performance Guarantee [Member]
Performance Guarantee [Member]
Settlement of equity settled awards
Settlement Of Other Equity Settled Awards
Settlement Of Other Equity Settled Awards
Accumulated other comprehensive loss
Accumulated other comprehensive loss, net of tax, beginning balance
Accumulated other comprehensive loss, net of tax, ending balance
Accumulated Other Comprehensive Income (Loss), Net of Tax
Environmental capital expenditures
Environmental Costs Recognized, Capitalized in Period
Expected return on plan assets
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets
Decrease in projected benefit obligation for curtailment
Curtailments
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment
Restricted cash and cash equivalents
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]
Net operating losses and tax credit carryforwards
Deferred Tax Assets Losses And Tax Credit Carryforwards
The tax effect as of the balance sheet date of the amount of future tax deductions arising from losses and unused tax credit carryforwards. A tax credit carryforward is the amount by which tax credits available for utilization exceeded statutory limits on inclusion in historical filings. They can only be utilized if sufficient tax-basis income is generated in future periods and providing tax laws continue to allow such utilization.
Total current assets
Assets, Current
Income and other taxes
Taxes Payable, Current
Maturity
Debt Instrument, Maturity Date
Income taxes paid
Net cash payments for income taxes
Income Taxes Paid, Net
Derivative instruments, income tax recovery (expense)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax
Increases for:
Increases [Abstract]
Schedule of activity under share repurchase programs
Schedule of Activity Under Share Repurchase Programs [Table Text Block]
Tabular disclosure of the information related to the share repurchase programs.
Revenue recognized included in the beginning balance
Contract with Customer, Liability, Revenue Recognized
Commercial Paper
Commercial Paper [Abstract]
Dividends (in dollars per share)
Common Stock, Dividends, Per Share, Declared
Intangible assets
Finite-Lived Intangible Assets, Net
Grain And Fertilizers [Member]
Grain And Fertilizers [Member]
Grain And Fertilizers [Member]
Summary of significant accounting policies
Significant Accounting Policies [Text Block]
Revolving Credit Facility, Tranche One [Member]
Revolving Credit Facility Tranche One [Member]
Revolving Credit Facility Tranche for $420 million maturing on May 5, 2019
Amortization of net actuarial loss, income tax recovery (expense)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax
Realized excess tax benefit
Share-Based Payment Arrangement, Exercise of Option, Tax Benefit
Defined Benefit Plan, Funding Status [Domain]
Defined Benefit Plan, Funding Status [Domain]
Roll forward of outstanding stock options
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]
Properties
Property, Plant and Equipment Disclosure [Text Block]
Absolute Return Funds [Member]
Absolute Return [Member]
A portfolio of units of externally managed hedge funds.
Ties installation, minimum level of activity to be capitalized
Property Plant And Equipment Cost Capitalization Minimum Level Of Activity Ties Per Minimum Level Of Activity Of Rail And Related Track Material
Describes the minimum level of activity of costs an entity capitalizes as part of property, plant and equipment, including the costs incurred for repairs and maintenance activities.
Approximate percentage of the Company's freight revenues from national accounts
Percentage Freight Revenues From National Accounts
Approximate percentage of company's freight revenues from national accounts.
Amortization of prior service cost (credit), net of tax
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax
Aggregate intrinsic value of options outstanding
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value
Property, Plant and Equipment, Type [Domain]
Long-Lived Tangible Asset [Domain]
Other liabilities and deferred credits
Other Noncurrent Liabilities [Table Text Block]
Cumulative loss
Gain (Loss) on Sale of Derivatives
Accumulated Depreciation
Finance Lease, Right-of-Use Asset, Accumulated Amortization
Leases
Lessee, Operating Lease, Description [Abstract]
Total operating expenses
Costs and Expenses
Total debt, gross
Long-term Debt, Gross And Lease Obligation
Long-term Debt, Gross And Lease Obligation
Debt Instrument [Line Items]
Debt Instrument [Line Items]
Business Combination and Asset Acquisition [Abstract]
Share Units Plan [Member]
Share Units Plan [Member]
Repurchase of common shares
Class of Stock [Line Items]
Bridge financing and other fees
Payments of Debt Issuance Costs
Present value of lease payments
Operating Lease, Liability
Weighted-average discount rate (%)
Leases, Weighted Average Discount Rate [Abstract]
Leases, Weighted Average Discount Rate [Abstract]
Stock-based compensation
Share-Based Payment Arrangement [Policy Text Block]
Total lease payments
Finance Lease, Liability, to be Paid
Schedule of finance lease maturities
Finance Lease, Liability, Fiscal Year Maturity [Table Text Block]
Pensions
Retirement Benefits, Description [Abstract]
Tax recovery
Tax Adjustments, Settlements, and Unusual Provisions
Derivative financial instruments related to equity exposure [Member]
Derivative Financial Instruments Related To Equity Exposure [Member]
Derivative Financial Instruments Related To Equity Exposure
Committed Bilateral Letter of Credit Facilites [Member]
Committed Bilateral Letter of Credit Facilites [Member]
Committed Bilateral Letter of Credit Facilities
Weighted average exercise price of options granted (in dollars per share)
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price
Canadian National series, 4.45% 30-year notes [Member]
CNR Two Thousand Forty Nine Thirty Year Notes [Member]
CNR Two Thousand Forty Nine Thirty Year Notes [Member]
Total finance lease cost
Finance Lease, Cost
Finance Lease, Cost
Beginning of year
End of year
Accrual for Environmental Loss Contingencies
Employee Share Investment Plan, Participants [Member]
Employee Share Investment Plan, Participants [Member]
Employee Share Investment Plan, Participants
2026
Long-Term Debt, Maturity, Year Four
Equipment rents
Equipment Rents
Rent paid for freight cars owned by other railroads or private companies, net of rents received, including lease expenses primarily for locomotives, railcars, containers and trailers, office and other rentals.
U.S. [Member]
UNITED STATES
Disclosures regarding the employee share investment plan
Employee Stock Ownership Plan (ESOP) Disclosures [Table Text Block]
Information for the pension plans with a projected benefit obligation in excess of plan assets
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]
Policy
Defined Benefit Plan, Plan Liabilities, Target Allocation, Percentage
Defined Benefit Plan, Plan Liabilities, Target Allocation, Percentage
Loss Contingency Accrual [Roll Forward]
Loss Contingency Accrual [Roll Forward]
Total stock-based compensation expense
Share-Based Payment Arrangement, Expense
Railroad Employees National Early Retirement Major Medical Benefit Plan [Member]
Railroad Employees National Early Retirement Major Medical Benefit Plan [Member]
Multiemployer plan name.
Weighted average exercise price per share of options outstanding at beginning of period (in dollars per share)
Weighted average exercise price per share of options outstanding at end of period (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price
Minimum term for which collateral in the form of cash and cash equivalents is pledged for
Line Of Credit Facility Collateral Minimum Term (in months)
Minimum term (in months) for which collateral in the form of cash and cash equivalents is pledged for.
Other Liabilities Disclosure [Abstract]
Other Liabilities Disclosure [Abstract]
Amortization of gain on treasury lock, net of tax
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax
Outstanding letters of credit
Letters of Credit Outstanding, Amount
Revenues
Revenue from Contract with Customer, Excluding Assessed Tax
Current service cost
Defined Benefit Plan, Service Cost
Accounts receivable
Accounts Receivable [Text Block]
Includes disclosure of amounts due from customers and others. This also provides for the disclosures pertaining to a transferor's continuing involvement in financial assets that it has transferred in a securitization arrangement.
Cover [Abstract]
Personal Injury & legal claims
Deferred Tax Assets Claims And Other Reserves
The tax effect as of the balance sheet date of the amount of the estimated future tax deductions arising from estimated losses from personal injury claims and other reserves, which can only be deducted for tax purposes when actual losses are incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken.
Depreciation and amortization
Depreciation, Depletion and Amortization, Nonproduction
Maximum percentage of gross salary employer can contribute toward purchase of Company's common stock
Share Based Compensation Arrangement By Share Based Payment Award Maximum Employer Subscription Rate
The highest percentage of annual salary that the employer will contribute toward purchase with respect to the plan.
Change In Contract With Customer, Liability [Roll Forward]
Change In Contract With Customer, Liability [Roll Forward]
Change In Contract With Customer, Liability [Roll Forward]
Finance leases
Finance Lease, Weighted Average Discount Rate, Percent
Revenues
Revenue from Contract with Customer [Text Block]
Schedule of Other Current Assets
Schedule of Other Current Assets [Table Text Block]
Segment Reporting [Abstract]
Segment Reporting [Abstract]
Settlement of foreign exchange forward contracts on debt
Proceeds From (Payments For) Settlement Of Foreign Exchange Forward Contracts On Long Term Debt, Financing Activities
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Weighted average grant date fair value per share of nonvested options outstanding at beginning of period (in dollars per share)
Weighted average grant date fair value per share of options outstanding at end of period (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Option, Nonvested, Weighted Average Exercise Price
Forecast [Member]
Forecast [Member]
Derivative instruments
Derivative Asset, Current
Risk-free interest rate
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate
Defined Benefit Plan, Plan Assets, Category [Axis]
Defined Benefit Plan, Plan Assets, Category [Axis]
Bilateral letter of credit facilities, collateral
Line of Credit Facility, Collateral, Amount
Amount of collateral pledged under letter of credit facilities.
Income tax recovery (expense), beginning balance
Income tax recovery (expense), ending balance
AOCI Tax, Attributable to Parent
Emerging market debt [Member]
Emerging Market Debt [Member]
This category includes information about long-term debt securities that are issued in the emerging market sector with a date certain promise of repayment and a return to the holder for the time value of money (for example, variable or fixed interest, original issue discount).
Amount of government assistance received
Government Assistance, Amount Received
Government Assistance, Amount Received
Amortization of net actuarial loss (gain)
Defined Benefit Plan, Amortization of Gain (Loss)
Retirement Plan Name [Axis]
Retirement Plan Name [Axis]
Discount rate
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate
Withholding taxes remitted on the net settlement of equity settled awards
Remittance of stock-based award participants' withholding tax obligation
Payment, Tax Withholding, Share-Based Payment Arrangement
Total liabilities and shareholders' equity
Liabilities and Equity
Assets held for sale
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment
Proceeds from asset held for sale
Proceeds from Sale of Property Held-for-sale
Amortization of bridge financing and other fees
Amortization of Debt Issuance Costs
Long-term Debt, Type [Axis]
Long-Term Debt, Type [Axis]
Absolute Return Funds, Foreign Exchange Forwards [Member]
Absolute Return Funds, Foreign Exchange Forwards [Member]
Absolute Return Funds, Foreign Exchange Forwards
Total deferred income tax assets
Deferred Tax Assets, Gross
Weighted-average grant date fair value
Share-Based Compensation Arrangement By Share-Based payment Award, Non-Option Equity Instruments, Weighted Average Grant Date Fair Value [Roll Forward]
Share-Based Compensation Arrangement By Share-Based payment Award, Non-Option Equity Instruments, Weighted Average Grant Date Fair Value [Abstract]
Settlement loss arising during the year, before tax
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax
Accrued interest and penalties
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued
Accounts payable and other
Accounts Payable and Accrued Liabilities Disclosure [Text Block]
Less: Imputed interest
Lessee, Operating Lease, Liability, Undiscounted Excess Amount
Diluted (in dollars per share)
Diluted earnings per share (in dollars per share)
Earnings Per Share, Diluted
Foreign Currency Risk Exposure by Currency [Domain]
Foreign Currency Risk Exposure by Currency [Domain]
Net unrecognized tax benefits at end of year
Net unrecognized tax benefits at end of year
Unrecognized tax benefits, net
Accumulated benefit obligation at end of year
Defined Benefit Plan, Accumulated Benefit Obligation
Number of years in the plan period over which the units will vest
Vesting period
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period
Current
Current Liability, Lessee [Abstract]
Current Liability, Lessee [Abstract]
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Share-Based Payment Arrangement, Additional Disclosure [Abstract]
Exercise Price Range [Domain]
Exercise Price Range [Domain]
Vested (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares
Employee Share Investment Plan [Member]
Employee Share Investment Plan [Member]
A company plan giving eligible employees the opportunity to subscribe to purchase shares of the company's common stock.
2024
Lessee, Operating Lease, Liability, to be Paid, Year Two
Other
Other Assets, Current
Non-Core Lines [Member]
Non-Core Lines [Member]
Non-Core Lines
Foreign exchange gain (loss) on translation of US dollar-denominated debt designated as a hedge of the net investment in foreign operations, net of tax
Other Comprehensive Income, Foreign Currency Gain (Loss) on Translation of Foreign Currency Denominated Long-term Debt Designated as a Hedge of Net Investment in Foreign Subsidiaries, Net of Tax
Amount after tax, and before reclassification adjustments of gain (loss) on translation of foreign currency denominated long-term debt designated as a hedge of net investment in foreign subsidiaries.
Canadian National series, 2.85% 10-year notes [Member]
CNR 2021 Notes [Member]
Canadian National series, 2.85% 10-year notes
Gross unrecognized tax benefits
Gross unrecognized tax benefits at beginning of year
Gross unrecognized tax benefits at end of year
Unrecognized Tax Benefits
Property additions, net of finance leases
Property, Plant and Equipment, Net, Excluding Capital Leased Assets [Abstract]
Share Repurchase Program [Axis]
Share Repurchase Program [Axis]
Amortization of prior service cost (credit), income tax recovery (expense)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax
Domestic
Income (Loss) from Continuing Operations before Income Taxes, Domestic
Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]
Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]
Other liabilities and deferred credits
Other Liabilities, Noncurrent [Abstract]
Cumulative Effect, Period of Adoption, Adjustment [Member]
Cumulative Effect, Period of Adoption, Adjustment [Member]
Rate to determine current service cost
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate
Equity, Class of Treasury Stock [Line Items]
Equity, Class of Treasury Stock [Line Items]
Schedule of operating lease maturities
Lessee, Operating Lease, Liability, Maturity [Table Text Block]
Long-term Purchase Commitment [Table]
Long-Term Purchase Commitment [Table]
Equipment Loan [Member]
Equipment Loan [Member]
Equipment Loan
Beginning of year
End of year
Contract with Customer, Liability
Product and Service [Axis]
Product and Service [Axis]
Absolute return [Member]
Hedge Funds [Member]
Expected return on plan assets
Expected return on plan assets
Defined Benefit Plan, Expected Return (Loss) on Plan Assets
Interest expense
Interest Expense
Weighted average grant date fair value per share of nonvested options that vested during the period (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value
Canadian National series, 4.40% 30-year notes [Member]
CNR 2052 Notes [Member]
CNR 2052 Notes
Government Assistance [Line Items]
Government Assistance [Line Items]
Stock option awards general disclosure
Share-based Compensation Arrangement by Share-based Payment Award, Options, General Disclosures [Abstract]
Dividend rate (in dollars per share)
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate Per Share
The estimated dividend rate (per share) to be paid (expected dividends) to holders of the underlying shares over the term.
Retirement Plan Type [Axis]
Retirement Plan Type [Axis]
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment [Line Items]
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) [Abstract]
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) [Abstract]
Schedule of debt
Schedule of Long-Term Debt Instruments [Table Text Block]
Building [Member]
Building [Member]
Derivative financial instruments related to bond exposure [Member]
Derivative Financial Instruments Related To Bond Exposure [Member]
Derivative Financial Instruments Related To Bond Exposure
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Share-Based Compensation Arrangement by Share-Based Payment Award, Additional General Disclosures [Abstract]
Settlement loss arising during the year, net of tax
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax
Funded status - Excess (deficiency) of fair value of plan assets over projected benefit obligation at end of year
Defined Benefit Plan, Funded (Unfunded) Status of Plan
Component representing future salary increases
Defined Benefit Portion Of Benefit Obligation From Future Salary Increases
The amount of the projected benefit obligation that is due to the anticipated salary increases from plan participants
Impairment loss, pre-tax
Impairment Of Long-Lived Assets To Be Disposed Of, Pre-Tax
Impairment Of Long-Lived Assets To Be Disposed Of, Pre-Tax
Other Commitments [Member]
Other Commitments [Member]
The Company has commitments to acquire railroad ties, rail, freight cars, locomotives, and other equipment and services, as well as outstanding information technology service contracts and licenses.
Lease right-of-use assets
Assets, Lessee [Abstract]
Assets, Lessee [Abstract]
Accounts Payable and Accrued Liabilities [Abstract]
Accounts Payable and Accrued Liabilities [Abstract]
Notes and debentures [Member]
Notes and Debentures [Member]
Guarantees and indemnifications
Guarantees And Indemnifications [Abstract]
Contributions to multi-employer plan
Multiemployer Plan, Employer Contribution, Cost
Disaggregation of revenue
Disaggregation of Revenue [Table Text Block]
Total deferred income tax liabilities
Deferred Tax Liabilities, Gross
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Abstract]
Other comprehensive income (loss)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent [Abstract]
Cost
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization
Plan participants' contributions
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant
Net unamortized discount and debt issuance costs
Unamortized discount and debt issuance costs, Net
Net unamortized discount and debt issuance costs related to long-term debt
Operating cash outflows from finance leases
Finance Lease, Interest Payment on Liability
Japanese Yen [Member]
Foreign Currency Risk Exposure to Japanese Yen [Member]
Maximum percentage of equity investments allocated to an individual issuer (in hundredths)
Defined Benefit Plan Maximum Percentage Of Equity Investments Allocated To Individual Issuer
Maximum percentage of equity investments allocated to an individual issuer during the period.
Maximum percentage of additional contribution made by the Company of amount invested by employee
Share Based Compensation Arrangement By Share Based Payment Award Maximum Employer Matching Rate
The Company will invest, on the employee's behalf, this percentage of the amount invested by the employees, up to 6 % of the employee's gross salary.
To determine net periodic benefit cost (income)
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Commercial paper [Member]
Commercial Paper [Member]
Measurement Frequency [Axis]
Measurement Frequency [Axis]
Canadian National series, 3.60% 30-year notes [Member]
CNR Two Thousand Forty-Eight Notes [Member]
CNR Two Thousand Forty-Eight Notes [Member]
Cash Settled Awards [Member]
Cash Settled Awards [Member]
Equity-based compensation award that is settleded by cash.
Weighted-average grant date fair value
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Provision for specific environmental sites
Schedule of Environmental Loss Contingencies by Site [Table Text Block]
Right-of-use assets obtained in exchange for lease liabilities ($)
Right-Of-Use Assets Obtained In Exchange For Lease Liabilities [Abstract]
Right-Of-Use Assets Obtained In Exchange For Lease Liabilities [Abstract]
Postretirement benefits other than pensions
Pension and Other Postretirement Plans, Nonpension Benefits, Policy [Policy Text Block]
Total Investment Assets [Member]
Total Investment Assets [Member]
This element is the total of the fair values of plan assets by major class as of the end of the reporting period, excluding the net operating assets required to administer the trust funds' investments assets and the plans' benefit and funding activities.
Accrued charges
Other Accrued Liabilities, Current
NCIB February 1, 2022 – January 31, 2023 (in shares)
NCIB February 1, 2023 – January 31, 2024 (in shares)
Stock Repurchase Program, Number of Shares Authorized to be Repurchased
Loss Contingency Nature [Axis]
Loss Contingency Nature [Axis]
Weighted average exercise price of options exercisable (in dollars per share)
Share-Based Payment Arrangement, Option, Exercise Price Range, Exercisable, Weighted Average Exercise Price
Long-term Debt, Type [Domain]
Long-Term Debt, Type [Domain]
Retirement Benefits [Abstract]
Retirement Benefits [Abstract]
Nonvested options outstanding at beginning of period (in shares)
Nonvested options outstanding at end of period (in shares)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested, Number of Shares
Statement of Stockholders' Equity [Abstract]
Statement of Stockholders' Equity [Abstract]
Canadian National series, 3.60% 30-year notes [Member]
Cnr 2047 Notes [Member]
This element includes 30-year notes due 2047.
Income tax expense at the Canadian statutory federal tax rate
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount
Schedule of lease assets and liabilities
Assets And Liabilities, Leases [Table Text Block]
Assets And Liabilities, Leases [Table Text Block]
Increase in net periodic benefit cost
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Increase (Decrease) for Plan Amendment
Less: Imputed interest
Finance Lease, Liability, Undiscounted Excess Amount
Payments
Loss Contingency Accrual, Payments
Issuance
Proceeds from Issuance of Commercial Paper
Disposal Group Classification [Domain]
Disposal Group Classification [Domain]
Pension liability
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Pensions
Treasury Lock [Member]
Treasury Lock [Member]
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Line Items]
Payments
Accrual for Environmental Loss Contingencies, Payments
Weighted average grant date fair value per share of nonvested options forfeited/cancelled (in dollars per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested Options Forfeited, Weighted Average Grant Date Fair Value
Finance leases included in properties
Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract]
Credit Default Swap [Member]
Bond, Credit Default Swap [Member]
Bond, Credit Default Swap
Deferred costs
Nontrade Receivables, Noncurrent
Projected benefit obligation
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation
Equity investments and derivative financial instruments [Member]
Equity Investments And Derivative Financial Instruments [Member]
Equity Investments And Derivative Financial Instruments
Schedule of issuances and repayments of commercial paper
Schedule of Gross Issuance Repayments Commercial Paper [Table Text Block]
Tabular disclosure of gross issuances and repayments information pertaining to commercial paper