v3.25.4
Employee Future Benefits - Life Expectancies (Detail) - yr
Dec. 31, 2025
Dec. 31, 2024
U.S. | Life expectancy (in years) for those currently age 65 | Males    
Disclosure of defined benefit plans [line items]    
Life expectancy (in years) 22,200,000 22,200,000
U.S. | Life expectancy (in years) for those currently age 65 | Females    
Disclosure of defined benefit plans [line items]    
Life expectancy (in years) 23,600,000 23,700,000
U.S. | Life expectancy (in years) at age 65 for those currently age 45 | Males    
Disclosure of defined benefit plans [line items]    
Life expectancy (in years) 23,600,000 23,600,000
U.S. | Life expectancy (in years) at age 65 for those currently age 45 | Females    
Disclosure of defined benefit plans [line items]    
Life expectancy (in years) 25,000,000.0 25,100,000
Canada | Life expectancy (in years) for those currently age 65 | Males    
Disclosure of defined benefit plans [line items]    
Life expectancy (in years) 24,400,000 24,400,000
Canada | Life expectancy (in years) for those currently age 65 | Females    
Disclosure of defined benefit plans [line items]    
Life expectancy (in years) 26,300,000 26,200,000
Canada | Life expectancy (in years) at age 65 for those currently age 45 | Males    
Disclosure of defined benefit plans [line items]    
Life expectancy (in years) 25,300,000 25,300,000
Canada | Life expectancy (in years) at age 65 for those currently age 45 | Females    
Disclosure of defined benefit plans [line items]    
Life expectancy (in years) 27,100,000 27,100,000