Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss by Component (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning balance	$ (245)
Other Comprehensive Income (Loss) before Reclassifications	476
Amounts reclassified from accumulated other comprehensive income (loss)	14
Accumulated Other Comprehensive Income (Loss), Ending balance	245
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning balance	(241)	[1]
Other Comprehensive Income (Loss) before Reclassifications	478	[1]
Amounts reclassified from accumulated other comprehensive income (loss)	14	[1]
Accumulated Other Comprehensive Income (Loss), Ending balance	251	[1]
Equity Method Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning balance	(4)
Other Comprehensive Income (Loss) before Reclassifications	(2)
Amounts reclassified from accumulated other comprehensive income (loss)	0
Accumulated Other Comprehensive Income (Loss), Ending balance	$ (6)

[1] Amounts are net of tax. See Note 13 for additional details.