CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 205	$ 188	$ 540	$ 584
Items related to employee benefit plans:
Change in net actuarial loss, net of $(16), $(2), $(46) and $(6) tax	24	3	74	9
Change in net prior service costs, net of $(3), $(2), $(8) and $(7) tax	4	3	12	11
Foreign currency translation adjustment and other	(10)	(16)	(10)	(7)
Other comprehensive income	18	(10)	76	13
COMPREHENSIVE INCOME	$ 223	$ 178	$ 616	$ 597