Stockholders' Equity (Schedule of Components of Other Comprehensive Income / (Loss)) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Components of Other Comprehensive Income (Loss) [Line Items]
Cumulative translation adjustment, pre-tax	$ 77	$ (457)	$ (6)
Cumulative translation adjustment, tax	0	0	0
Cumulative translation adjustment, after-tax	77	(457)	(6)
Additions and revaluations of derivatives designated as cash flow hedges, pre-tax	8	10	(33)
Additions and revaluations of derivatives designated as cash flow hedges, tax	(6)	(5)	14
Additions and revaluations of derivatives designated as cash flow hedges, after-tax	2	5	(19)
Clearance of hedge results to earnings, pre-tax	(65)	96	90
Clearance of hedge results to earnings, tax	28	(36)	(34)
Clearance of hedge results to earnings, after-tax	(37)	60	56
Net revaluation and clearance of cash flow hedges to earnings, pre-tax	(57)	106	57
Net revaluation and clearance of cash flow hedges to earnings, tax	22	(41)	(20)
Net revaluation and clearance of cash flow hedges to earnings, after-tax	(35)	65	37
Unrealized gain (loss) on securities arising during the period, pre-tax	(5)	2	(3)
Unrealized gain (loss) on securities arising during the peiod, tax	2	(1)	1
Unrealized gain (loss) on securities arising during the period, after-tax	(3)	1	(2)
Reclassification of loss realized in net income, pre-tax	3	0	5
Reclassification of loss realized in net income, tax	(1)	0	(2)
Reclassification of loss realized in net income, after-tax	2	0	3
Net unrealized (loss) gain on securities, pre-tax	(2)	2	2
Net unrealized (loss) gain on securities, tax	1	(1)	(1)
Net unrealized (loss) gain on securities, after-tax	(1)	1	1
Other comprehensive income (loss), before tax	253	(4,300)	(12)
Other comprehensive income (loss), tax	(121)	1,322	(5)
Other comprehensive income (loss), after-tax	132	(2,978)	(17)
Pension Plans, Defined Benefit [Member]
Components of Other Comprehensive Income (Loss) [Line Items]
Net loss, pre-tax	(1,433)	(4,069)	(635)
Net loss, tax	437	1,402	224
Net loss, after-tax	(996)	(2,667)	(411)
Prior service benefit (cost), pre-tax	22	(2)	0
Prior service benefit (cost), tax	(8)	0	0
Prior service benefit (cost), after-tax	14	(2)	0
Amortization of prior service cost (benefit), pre-tax	13	16	16
Amortization of prior service cost (benefit), tax	(4)	(5)	(5)
Amortization of prior service cost (benefit), after-tax	9	11	11
Amortization of loss, pre-tax	887	613	507
Amortization of loss, tax	(305)	(210)	(173)
Amortization of loss, after-tax	582	403	334
Curtailment / settlement loss, pre-tax	7	0	0
Curtailment / settlement loss, tax	(2)	0	0
Curtailment / settlement, after-tax	5	0	0
Benefit plans, net, pre-tax	(504)	(3,442)	(112)
Benefit plans, net, tax	118	1,187	46
Benefit plans, net, after-tax	(386)	(2,255)	(66)
Other Long-Term Employee Benefit Plans Defined Benefit [Member]
Components of Other Comprehensive Income (Loss) [Line Items]
Net loss, pre-tax	(60)	(437)	(94)
Net loss, tax	17	151	31
Net loss, after-tax	(43)	(286)	(63)
Prior service benefit (cost), pre-tax	857	(11)	189
Prior service benefit (cost), tax	(299)	4	(77)
Prior service benefit (cost), after-tax	558	(7)	112
Amortization of prior service cost (benefit), pre-tax	(155)	(121)	(106)
Amortization of prior service cost (benefit), tax	54	43	37
Amortization of prior service cost (benefit), after-tax	(101)	(78)	(69)
Amortization of loss, pre-tax	94	60	58
Amortization of loss, tax	(33)	(21)	(21)
Amortization of loss, after-tax	61	39	37
Curtailment / settlement loss, pre-tax	3	0	0
Curtailment / settlement loss, tax	(1)	0	0
Curtailment / settlement, after-tax	2	0	0
Benefit plans, net, pre-tax	739	(509)	47
Benefit plans, net, tax	(262)	177	(30)
Benefit plans, net, after-tax	$ 477	$ (332)	$ 17