Stockholder's Equity (Schedule of Accumulated Other Comprehensive Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2011
Components of Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive loss, ending balance	$ (8,662)	$ (8,465)	$ (8,646)	$ (8,750)
Other Comprehensive Income (Loss), before reclassification adjustment	(209)	170
Other Comprehensive Income (Loss), before reclassifications, of cash flow hedges	(9)	(2)
Other Comprehensive Income (Loss) Before Reclassification Adjustments	(165)	162
Other comprehensive income amounts reclassified from accumulated other comprehensive income (loss)	149	123
Cumulative Translation Adjustment [Member]
Components of Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive loss, ending balance	(376)	(74)	(167)	(244)
Other Comprehensive Income (Loss), before reclassification adjustment	(209)	170
Cumulative translation adjustment reclassified from accumulated other comprehensive income (loss)	0	0
Net Revaluation and Clearance of Cash Flow Hedges to Earnings
Components of Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive loss, ending balance	(12)	18	3	41
Other Comprehensive Income (Loss), before reclassifications, of cash flow hedges	(9)	(4)
CF hedges reclassified from accumulated other comprehensive income (loss)	(6)	(19)
Pension Plans [Member]
Components of Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive loss, ending balance	(8,375)	(8,134)	(8,686)	(8,276)
Other Comprehensive Income Before Reclassification Adjustments for Pension and Other Postretirement Benefit Plans	42	(5)
Pension benefit plans, amounts reclassified from accumulated other comprehensive income (loss)	269	147
Other Long-Term Employee Benefit Plans Defined Benefit [Member]
Components of Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive loss, ending balance	101	(279)	202	(274)
Other Comprehensive Income Before Reclassification Adjustments for Pension and Other Postretirement Benefit Plans	11	0
Other benefit plans adjustment reclassified from accumulated other comprehensive income (loss)	(112)	(5)
Unrealized Gain (Loss) on Securities
Components of Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive loss, ending balance	0	4	2	3
Other Comprehensive Income (Loss), before reclassifications, Unrealized Gain (Loss) on Securities	0	1
Unrealized gain (loss) on securities, amounts reclassified from accumulated other comprehensive income (loss)	$ (2)	$ 0