Accumulated Other Comprehensive Loss (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
INCOME BEFORE INCOME TAX EXPENSE									$ (1,110)	$ (224)	$ (1,250)
Income tax expense									(338)	(463)	(473)
Other income, net									11	59	35
NET INCOME (LOSS)	188	188	193	203	239	(1,045)	269	298	772	(239)	777
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net actuarial loss									85	88
Prior service cost									25	5
INCOME BEFORE INCOME TAX EXPENSE									(110)	(93)
Income tax expense									(42)	(35)
Other income, net									1	(1)
NET INCOME (LOSS)									$ 69	$ (59)