Stock-based compensation	6 Months Ended
Jun. 30, 2026
Share-Based Payment Arrangement [Abstract]
Stock-based compensation	Stock-based compensation As at June 30, 2026, the Company had several stock-based compensation plans including stock option plans, various cash‑settled liability plans, and an employee share purchase plan. These plans resulted in an expense for the three and six months ended June 30, 2026 of $94 million and $143 million, respectively (three and six months ended June 30, 2025 - $59 million and $92 million, respectively). Stock options plan In the six months ended June 30, 2026, under the Company’s stock option plan, the Company issued 1,189,411 options at the weighted-average price of $104.69 per share, based on the closing price of the Company's Common Shares on the TSX at the grant date. Pursuant to the employee plan, these options may be exercised upon vesting, which is between 12 months and 48 months after the grant date, and will expire seven years from the grant date. Under the fair value method, the fair value of the stock options at the grant date was approximately $30 million. Performance share unit plans During the six months ended June 30, 2026, the Company issued 629,722 Performance Share Units ("PSUs") with a grant date fair value of $66 million and 20,386 Performance Deferred Share Units ("PDSUs") with a grant date fair value, including the fair value of expected future matching units, of $3 million. PSUs and PDSUs attract dividend equivalents in the form of additional units based on dividends paid on the Company’s Common Shares, and vest three to four years after the grant date, contingent on the Company’s performance ("performance factor"). Vested PSUs are settled in cash. Vested PDSUs are converted into Deferred Share Units ("DSUs") pursuant to the DSU plan, are eligible for a 25% Company match if the employee has not exceeded their Common Share ownership requirements, and are settled in cash only when the holder ceases their employment with the Company. The performance period for all PSUs and all PDSUs granted in the six months ended June 30, 2026 is January 1, 2026 to December 31, 2028 and the performance factors are Free Cash Flow ("FCF"), Total Shareholder Return ("TSR") compared to the Standard and Poor's ("S&P")/TSX 60 Index, and TSR compared to the S&P 500 Industrials Index. The performance period for the 544,175 PSUs and 26,333 PDSUs granted in 2023 was January 1, 2023 to December 31, 2025, and the performance factors were FCF, Earnings Before Interest, Taxes, Depreciation, and Amortization ("EBITDA"), TSR compared to the S&P/TSX 60 Index, TSR compared to the S&P 500 Industrials Index, and TSR compared to other Class I railways. The resulting payout was 91% of the outstanding units multiplied by the Company's average Common Share price calculated based on the last 30 trading days preceding December 31, 2025. In the first quarter of 2026, payouts were $42 million on 461,766 PSUs, including dividends reinvested. The 26,555 PDSUs that vested on December 31, 2025, with a fair value of $3 million, including dividends reinvested and matching units, will be paid out in future reporting periods pursuant to the DSU plan (as described above).

As at June 30, 2026, the Company had several stock-based compensation plans including stock option plans, various cash‑settled liability plans, and an employee share purchase plan. These plans resulted in an expense for the three and six months ended June 30, 2026 of $94 million and $143 million, respectively (three and six months ended June 30, 2025 - $59 million and $92 million, respectively).

In the six months ended June 30, 2026, under the Company’s stock option plan, the Company issued 1,189,411 options at the weighted-average price of $104.69 per share, based on the closing price of the Company's Common Shares on the TSX at the grant date. Pursuant to the employee plan, these options may be exercised upon vesting, which is between 12 months and 48 months after the grant date, and will expire seven years from the grant date.

During the six months ended June 30, 2026, the Company issued 629,722 Performance Share Units ("PSUs") with a grant date fair value of $66 million and 20,386 Performance Deferred Share Units ("PDSUs") with a grant date fair value, including the fair value of expected future matching units, of $3 million. PSUs and PDSUs attract dividend equivalents in the form of additional units based on dividends paid on the Company’s Common Shares, and vest three to four years after the grant date, contingent on the Company’s performance ("performance factor"). Vested PSUs are settled in cash. Vested PDSUs are converted into Deferred Share Units ("DSUs") pursuant to the DSU plan, are eligible for a 25% Company match if the employee has not exceeded their Common Share ownership requirements, and are settled in cash only when the holder ceases their employment with the Company.

The performance period for all PSUs and all PDSUs granted in the six months ended June 30, 2026 is January 1, 2026 to December 31, 2028 and the performance factors are Free Cash Flow ("FCF"), Total Shareholder Return ("TSR") compared to the Standard and Poor's ("S&P")/TSX 60 Index, and TSR compared to the S&P 500 Industrials Index.

The performance period for the 544,175 PSUs and 26,333 PDSUs granted in 2023 was January 1, 2023 to December 31, 2025, and the performance factors were FCF, Earnings Before Interest, Taxes, Depreciation, and Amortization ("EBITDA"), TSR compared to the S&P/TSX 60 Index, TSR compared to the S&P 500 Industrials Index, and TSR compared to other Class I railways. The resulting payout was 91% of the outstanding units multiplied by the Company's average Common Share price calculated based on the last 30 trading days preceding December 31, 2025. In the first quarter of 2026, payouts were $42 million on 461,766 PSUs, including dividends reinvested. The 26,555 PDSUs that vested on December 31, 2025, with a fair value of $3 million, including dividends reinvested and matching units, will be paid out in future reporting periods pursuant to the DSU plan (as described above).