Accumulated Other Comprehensive Income by Component (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning balance	$ 245		$ (245)
Other Comprehensive Income (Loss) before Reclassifications	4		(2)
Amounts reclassified from accumulated other comprehensive income (loss)	(1)		10
Accumulated Other Comprehensive Income (Loss), Ending balance	248		(237)
Equity Method Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning balance	(6)		(4)
Other Comprehensive Income (Loss) before Reclassifications	4		(2)
Amounts reclassified from accumulated other comprehensive income (loss)	0		0
Accumulated Other Comprehensive Income (Loss), Ending balance	(2)		(6)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning balance	251	[1]	(241)	[1]
Other Comprehensive Income (Loss) before Reclassifications	0	[1]	0	[1]
Amounts reclassified from accumulated other comprehensive income (loss)	(1)	[1]	10	[1]
Accumulated Other Comprehensive Income (Loss), Ending balance	$ 250	[1]	$ (231)	[1]

[1] Amounts are net of tax.