Pension and Other Postretirement Benefits - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Decrease in obligation, pension benefits	$ 19
Pension plan settlements		$ (2)	$ (3)	$ (5)	$ (7)
Contributions and payments		9	18	28	43
Pension benefits
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Benefit obligation		2		5
Pension plan settlements		(2)	(3)	(5)	(7)
Pension benefits | US
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pension plan settlements					(7)
Pension benefits | Canada
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Decrease in obligation, pension benefits		12		$ 12
Pension plan settlements		$ (2)
Pension benefits | United States and Canada
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pension plan settlements			$ (3)		$ (7)