Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net income	$ 392	$ 722	$ 773	$ 1,399
Other comprehensive income, before tax:
Pension and other postretirement benefits	6	5	13	10
Other comprehensive income, before tax	7	5	19	9
Income tax expense related to items of other comprehensive income	(1)	(2)	(3)	(3)
Other comprehensive income, net of tax	6	3	16	6
Total comprehensive income	398	725	789	1,405
Accumulated Other Comprehensive Loss Equity Investees
Other comprehensive income, before tax:
Other comprehensive income, before tax	$ 1	$ 0	$ 6	$ (1)