CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss), AOCI, Pension and Postretirement Benefit Plans, Reclassification Adjustment for Net Gain (Loss) and Net Unamortized Gain (Loss) Arising During Period, Net of Tax	$ 742	$ (606)	$ 432
Other Comprehensive (Income) Loss, Pension and Postretirement Benefit Plans, Net Prior Service Cost (Credit) Amortization Adjustment and Arising During Period, Tax	1	52	4
Auction rate securities marked to market, tax	0	0	1
Auction rate securities settlements reclassified to net income, tax	(1)	0	1
Foreign currency translation adjustment and other, tax	$ 1	$ 0	$ 0