Employee retirement benefits, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets (Detail) - CAD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
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| Retirement Benefits [Abstract] | ||
| Projected benefit obligation | $ 409 | $ 431 |
| Accumulated benefit obligation | $ 368 | $ 386 |
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- References No definition available.
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- Definition Amount of accumulated benefit obligation for defined benefit plan with accumulated benefit obligation in excess of plan assets. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of projected benefit obligation for defined benefit pension plan with accumulated benefit obligation in excess of plan assets. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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