Financial instruments	3 Months Ended
Financial instruments	Mar. 31, 2024
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 $21,848 million as at March 31, 2024 (December 31, 2023 - $21,437 million), had a fair value of $20,449 million (December 31, 2023 - $20,550 million). B. Financial risk management FX management Net investment hedge The effect of the Company's net investment hedge included in "Other comprehensive income (loss)" for the three months ended March 31, 2024 was an unrealized FX loss of $103 million (three months ended March 31, 2023 - unrealized FX loss of $1 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 net monetary assets or liabilities denominated in Mexican pesos that are subject to periodic re-measurement and settlement that create fluctuations within "Other (income) expense". The Company has hedged its net exposure to Mexican peso/U.S dollar fluctuations in earnings with foreign currency forward contracts. The foreign currency forward contracts involve the Company’s agreement to buy or sell pesos at an agreed-upon exchange rate on a future date. The Company measures the foreign currency derivative contracts at fair value each period and recognizes any change in "Other (income) expense". The cash flows associated with these instruments are classified as "Operating activities" within the Interim Consolidated Statements of Cash Flows. During the three months ended March 31, 2024, the Company recorded a loss of $4 million related to foreign exchange currency forwards. As at December 31, 2023, the fair value of outstanding foreign exchange contracts included in "Accounts payable and accrued liabilities" was $60 million. As of January 12, 2024, the Company settled all outstanding foreign currency forward contracts, resulting in a cash outflow of $65 million. Offsetting The Company’s foreign currency forward contracts are executed with counterparties in the U.S. and are governed by International Swaps and Derivatives Association agreements that include standard netting arrangements. Asset and liability positions from contracts with the same counterparty are net settled upon maturity/expiration and presented on a net basis in the Interim Consolidated Balance Sheets prior to settlement.