CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Net sales (Note 3)	$ 1,671	$ 1,910	$ 5,006	$ 5,840
Costs of sales	1,399	1,452	4,111	4,247
Gross margin	272	458	895	1,593
Selling expenses	20	20	62	66
General and administrative expenses	85	78	254	236
Research and development expenses	1	2	4	6
Product remediation recoveries, net (Note 15)	(68)	0	(68)	0
Other operating costs, net (Note 17)	32	21	81	68
Operating income	202	337	562	1,217
Non-operating pension and other postretirement benefit costs	(15)	(17)	(495)	(54)
Interest income and other	6	13	22	36
Interest expense, net of capitalized interest	(91)	(93)	(289)	(278)
Earnings (loss) before income taxes	102	240	(200)	921
Income taxes (Note 18)	(3)	15	138	(80)
Net earnings (loss)	$ 99	$ 255	$ (62)	$ 841
Earnings (loss) per share, basic and diluted (Note 4)	$ 0.13	$ 0.34	$ (0.08)	$ 1.11
Weighted average shares outstanding (in thousands) (Note 4):
Basic	745,626	754,986	745,901	756,531
Diluted	746,514	757,389	745,901	759,116