Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 161	$ 96	$ 335	$ 452
Postretirement and postemployment plans:
Change in actuarial loss in postretirement and postemployment plans	(9)	13	(13)	17
Postretirement and postemployment plans, net of tax	(9)	13	(13)	17
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax	0	4	0	4
Other comprehensive income (loss)	(9)	17	(13)	21
Comprehensive income	$ 152	$ 113	$ 322	$ 473

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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