CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 878	$ 772	$ (239)
Items related to employee benefit plans:
Change in net actuarial gain (loss), net of $(12), $742 and $(606) tax	21	(1,200)	981
Change in net prior service credit (costs), net of $(47), $1 and $52 tax	76	(1)	(84)
Foreign currency translation adjustment and other, net of $-, $1 and $- tax	(14)	(14)	2
Other comprehensive income (loss)	83	(1,215)	899
COMPREHENSIVE INCOME (LOSS)	$ 961	$ (443)	$ 660