Financial instruments	3 Months Ended
Financial instruments	Mar. 31, 2025
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial instruments	Financial instruments A. Fair values of financial instruments The Company categorizes its financial assets and liabilities measured at fair value into a three-level hierarchy that prioritizes those inputs to valuation techniques used to measure fair value based on the degree to which they are observable. The three levels of the fair value hierarchy are as follows: Level 1 inputs are quoted prices in active markets for identical assets and liabilities; Level 2 inputs, other than quoted prices included within Level 1, are observable for the asset or liability either directly or indirectly; and Level 3 inputs are not observable in the market. The Company’s short-term financial instruments include cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities, and short-term borrowings, including commercial paper and term loans. The carrying value of short-term financial instruments approximate their fair value. The carrying value of the Company’s debt does not approximate its fair value. The estimated fair value has been determined based on market information, where available, or by discounting future payments of principal and interest at estimated interest rates expected to be available to the Company at the balance sheet date. All measurements are classified as Level 2. The Company’s long-term debt, including current maturities, with a carrying value of $21,523 million as at March 31, 2025 (December 31, 2024 - $20,749 million), had a fair value of $19,853 million (December 31, 2024 - $18,911 million). B. Financial risk management FX management Net investment hedge The majority of the Company’s U.S. dollar-denominated long-term debt, finance lease obligations, and operating lease liabilities have been designated as a hedge of the Company's net investment in foreign subsidiaries. This designation has the effect of mitigating volatility on Net income by offsetting long-term FX gains and losses on U.S. dollar-denominated long-term debt and gains and losses on its net investment. The effect of the Company's net investment hedge included in "Other comprehensive (loss) income" for the three months ended March 31, 2025 was an unrealized FX gain of $6 million (three months ended March 31, 2024 - unrealized FX loss of $103 million). Mexican Peso- U.S. dollar FX Forward contracts The Company’s Mexican subsidiaries have net U.S. dollar-denominated monetary assets or liabilities which, for Mexican income tax purposes, are subject to periodic revaluation based on changes in the value of the Mexican peso ("Ps.") against the U.S dollar. This revaluation creates fluctuations in the Company’s Mexican income tax expense and the amount of income taxes paid in Mexican pesos. The Company also has monetary assets or liabilities denominated in Mexican pesos that are subject to periodic re-measurement and settlement that create fluctuations within "Other expense (income)". Until January 2024, the Company had hedged its net exposure to Ps./U.S. dollar fluctuations in earnings with foreign currency forward contracts. The foreign currency forward contracts involved the Company’s agreement to buy or sell Ps. at an agreed-upon exchange rate on a future date. The Company measured the foreign currency derivative contracts at fair value each period and recognized any change in "Other expense (income)". The cash flows associated with these instruments were classified as "Operating activities" in the Interim Consolidated Statements of Cash Flows. The Company’s foreign currency forward contracts were executed with counterparties in the U.S. and were governed by International Swaps and Derivatives Association agreements that included standard netting arrangements. On January 12, 2024, the Company settled all outstanding foreign currency forward contracts, resulting in a cash outflow of $65 million. During the three months ended March 31, 2025, the Company recorded $nil related to foreign exchange currency forwards (three months ended March 31, 2024 - loss of $4 million). As of March 31, 2025 the Company had no outstanding foreign currency forward contracts (December 31, 2024 - $nil).