CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
NET INCOME (LOSS)	$ 377	$ 371	$ 691	$ (5,794)
Items related to employee benefit plans:
Change in net actuarial loss, net of $(13), $(14), $(25) and $(28) tax	39	42	77	85
Change in net prior service credit, net of $(1), $—, $(1) and $(1) tax	2	2	3	3
Reclassification of realized loss on interest rate swaps to net income, net of $(5), $—, $(5) and $— tax	11	0	16	0
Unrealized holding loss on interest rate swaps, net of $2, $8, $28 and $14 tax	(8)	(26)	(88)	(43)
Foreign currency translation adjustment and other net of $(4), $3, $19 and $2 tax	9	(8)	(230)	(3)
Other comprehensive income (loss)	53	10	(222)	42
COMPREHENSIVE INCOME (LOSS)	$ 430	$ 381	$ 469	$ (5,752)