CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Comprehensive income:
Net income	$ 603	$ 527	$ 1,185	$ 1,080
Pension and retiree medical benefits:
Net pension and retiree medical losses arising during the period, net of tax of $—, $—, $— and $1, respectively	0	0	0	2
Net pension gains, tax	0	0	0	1
Amortization of losses included in net periodic benefit cost, net of tax of $—, $—, $1 and $1, respectively	1	1	4	3
Pension reclassification's, Tax	0	0	1	1
Derivative instruments:
Net fair value decrease, net of tax of $—, $(3), $(3) and $(8), respectively	0	(9)	(10)	(25)
Derivative fair value decrease, tax	0	(3)	(3)	(8)
Reclassification of losses to net income, net of tax of $—, $—, $1 and $1, respectively	1	1	4	2
Derivative reclassification's, tax	0	0	1	1
Total comprehensive income	605	520	1,183	1,062
Other comprehensive income	$ 2	$ (7)	$ (2)	$ (18)