Fair Value Measurements (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Schedule of Investments [Line Items]
Cash	$ 157	$ 121
Cash and Cash Equivalents
Cash equivalents:
Cost Basis	2,192	1,628
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	2,192	1,628
U.S. and Canadian government obligations | Cash and Cash Equivalents
Cash equivalents:
Cost Basis	1,813	1,452
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	1,813	1,452
Other debt securities | Cash and Cash Equivalents
Cash equivalents:
Cost Basis	222	55
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	222	55
Nonqualified employee benefit trusts
Cash equivalents:
Cost Basis	16	17
Unrealized Gains	0	3
Unrealized Losses	0	0
Fair Value	$ 16	$ 20