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)		$ (522)	$ 4,131	$ 1,311
Other comprehensive income (loss) items:
Foreign currency translation gains		0	0	3
Unrealized gains (losses) on derivatives	[1]	(129)	(6)	13
Pension and postretirement gains (losses)	[2]	78	137	(7)
Reclassification of realized losses (gains) on derivatives	[3]	2	13	(1)
Other comprehensive income (loss), net of tax		(49)	144	8
Comprehensive income (loss)		(571)	4,275	1,319
Less: Comprehensive income attributable to noncontrolling interests		(145)	0	0
Comprehensive income (loss) attributable to preferred and common stockholders		$ (716)	$ 4,275	$ 1,319

[1] Net of tax of $36, $2 and $(7) in 2019, 2018 and 2017, respectively.

[2] Net of tax of $(25), $(38) and $4 in 2019, 2018 and 2017, respectively. See Note 15 - Retirement and Postretirement Benefit Plans in the Notes to Consolidated Financial Statements for additional information.

[3] Net of tax of $0, $(4) and $0 in 2019, 2018 and 2017, respectively.