CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 272	$ 92	$ 679	$ 272
Items related to employee benefit plans:
Change in net actuarial loss, net of $(11), $(15), $(33) and $(57) tax	34	36	102	97
Change in net prior service costs, net of $—, $(1), $(2) and $(3) tax	3	2	7	6
Foreign currency translation adjustment and other, net of $(1), $—, $29 and $— tax	(1)	18	(161)	20
Other comprehensive income (loss)	36	56	(52)	123
COMPREHENSIVE INCOME	$ 308	$ 148	$ 627	$ 395