Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 1,371	$ 1,251
Other comprehensive income:
Change in pension and retiree health and welfare benefits, net of tax	1	1
Change in accumulated other comprehensive income (loss) of equity method investees	4	0
Other comprehensive income (loss), net of tax	5	1
Total comprehensive income	$ 1,376	$ 1,252