CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) [Abstract]
Settlements tax	$ (81)	$ 10	$ (124)
Ineffectiveness tax	0	0	1
Change in fair value of derivative instruments tax	16	49	16
Current period net gain (loss) tax	0	(10)	8
Amortization of prior service cost and net loss included in net periodic pension cost tax	$ 0	$ 0	$ 1