CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 92	$ 152	$ 272	$ 584
Items related to employee benefit plans:
Change in net actuarial loss, net of $(15), $(16), $(57) and $(49) tax	36	28	97	82
Change in net prior service costs, net of $(1), $(1), $(3) and $(3) tax	2	2	6	6
Foreign currency translation adjustment and other, net of $—, $—, $— and $— tax	18	(4)	20	(9)
Other comprehensive income	56	26	123	79
COMPREHENSIVE INCOME	$ 148	$ 178	$ 395	$ 663