Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Comprehensive Income [Line Items]
Net Unrealized Gain/(Loss) on Investments	$ (29)
Benefit Obligations	(124)
Foreign Currency Translation	1
Accumulated Other Comprehensive Loss	(156)		(158)
Current period change, net of tax Foreign Currency Translation	(1)	1
Other Comprehensive Income Before Reclassifications	(1)
Amounts Reclassified From Accumulated Other Comprehensive Income	3
Derivative Financial Instruments, Assets [Member]
Comprehensive Income [Line Items]
Net Unrealized Gain/(Loss) on Derivaive	(4)		(4)
Current period change, net of tax Net Unrealized Gain/(Loss) on Derivatives Gain (Loss) on Derivatives Arising During Period, Net of Tax	0
Other Comprehensive Income Before Reclassifications	0
Amounts Reclassified From Accumulated Other Comprehensive Income	0
Investments [Member]
Comprehensive Income [Line Items]
Net Unrealized Gain/(Loss) on Investments			(29)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	0
Other Comprehensive Income Before Reclassifications	0
Amounts Reclassified From Accumulated Other Comprehensive Income	0
Pension Plans, Defined Benefit [Member]
Comprehensive Income [Line Items]
Benefit Obligations			(127)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	3
Other Comprehensive Income Before Reclassifications	0
Amounts Reclassified From Accumulated Other Comprehensive Income	3
Foreign Currency Gain (Loss) [Member]
Comprehensive Income [Line Items]
Foreign Currency Translation			2
Current period change, net of tax Foreign Currency Translation	(1)
Other Comprehensive Income Before Reclassifications	(1)
Amounts Reclassified From Accumulated Other Comprehensive Income	$ 0