CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Net sales (Note 3)	$ 1,631	$ 1,692	$ 3,359	$ 3,335
Costs of sales	1,283	1,390	2,665	2,712
Gross margin	348	302	694	623
Selling expenses	18	21	40	42
General and administrative expenses	84	80	158	169
Other operating costs, net (Note 15)	3	15	13	52
Operating income	243	186	483	360
Non-operating pension and other postretirement benefit costs (Note 7)	(10)	(10)	(19)	(480)
Interest income and other	2	6	3	16
Interest expense, net of capitalized interest	(103)	(91)	(188)	(198)
Earnings (loss) before income taxes	132	91	279	(302)
Income taxes (Note 16)	(60)	37	(57)	141
Net earnings (loss)	$ 72	$ 128	$ 222	$ (161)
Earnings (loss) per share, basic and diluted (Note 4)	$ 0.10	$ 0.17	$ 0.30	$ (0.22)
Weighted average shares outstanding (in thousands) (Note 4):
Basic	746,896	745,486	746,715	746,041
Diluted	746,984	746,232	747,070	746,041