Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 1,347	$ 1,466	$ 3,668	$ 4,057
Other comprehensive income:
Change in pension and retiree health and welfare benefits, net of tax	0	0	1	63
Change in accumulated other comprehensive income (loss) of equity method investees	0	0	1	(1)
Other comprehensive income (loss), net of tax	0	0	2	62
Total comprehensive income	$ 1,347	$ 1,466	$ 3,670	$ 4,119