Consolidated Statements of Comprehensive Income - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ 99	$ 429	$ (262)
Net income attributable to noncontrolling interests		(127)	(101)	(4)
Other comprehensive income (loss) items:
Reclassification of unrealized gains (losses) on pension and postretirement losses	[1]	(24)	13	(14)
Reclassification of realized losses on pension and postretirement to income	[1]	7	4	5
Total other comprehensive income (loss)		(17)	17	(9)
Comprehensive (loss) income attributable to common stock		$ (45)	$ 345	$ (275)

[1] No associated tax for 2019, 2018 and 2017. See Part II, Item 8 Financial Statements and Supplementary Data, Note 14 Pension and Postretirement Benefit Plans for additional information.