CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - 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 (Loss)	$ (945)	$ 17	$ (849)	$ 191
Adjustments for derivative instruments
Reclassification of previously deferred derivative losses to (gains) losses on derivatives, net	0	0	1	1
Total adjustments for derivative instruments, net of taxes	0	0	1	1
Adjustments for pension and other postretirement plans
Net gain (loss) incurred during period	(80)	0	(80)	0
Income taxes on net gain (loss) incurred during period	18	0	18	0
Amortization of net actuarial (gain) loss to other (income) expense, net	16	6	24	13
Income taxes on amortization of net actuarial (gain) loss	(4)	(1)	(6)	(3)
Amortization of net prior service (credit) cost to other (income) expense, net	0	(6)	(1)	(12)
Income taxes on amortization of net prior service (credit) cost	0	1	0	2
Total adjustments for pension and other postretirement plans, net of taxes	(50)	0	(45)	0
Total	(50)	0	(44)	1
Comprehensive Income (Loss)	(995)	17	(893)	192
Comprehensive income (loss) attributable to noncontrolling interests	80	(12)	191	41
Comprehensive Income (Loss) Attributable to Common Stockholders	$ (1,075)	$ 29	$ (1,084)	$ 151