Pension and Other Postretirement Employee Benefit Plans - Defined Benift Pension Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan, Changes in Benefit Obligations and Plan Assets and Funded Status Amounts [Abstract]
Defined Contribution Plan Employer Matching Contribution Percent	5.00%
Defined Contribution Plan Employee Annual Compensation Amount Not Eligible For Employers Matching Contributions	$ 250,000
Defined Benefit Pension Plans and OPEB Plans [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of year	(999,000,000)	(980,000,000)
Defined Benefit Plan, Service Cost	(1,000,000)	(1,000,000)	(2,000,000)
Interest cost on benefit obligations	(44,000,000)	(51,000,000)	(55,000,000)
Plan amendments	0	0
Business combinations	0	0
Defined Benefit Plan Contributions By Plan Participants Benefit Obligation	(74,000,000)	(84,000,000)
Net gain/(loss)	(9,000,000)	(39,000,000)
Defined Benefit Plan Benefits Paid Benefit Obligation	149,000,000	166,000,000
Expected Medicare Part D subsidy receipts	(10,000,000)	(10,000,000)
Foreign exchange impact and other	(2,000,000)	0
Benefit obligation, end of year	(990,000,000)	(999,000,000)	(980,000,000)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	1,435,000,000	1,381,000,000
Actual return on plan assets	142,000,000	78,000,000
Firm contributions	2,000,000	2,000,000
Employee contributions	0	0
Benefits paid	(16,000,000)	(26,000,000)
Foreign exchange impact and other	0	0
Fair value of plan assets, end of year	1,563,000,000	1,435,000,000	1,381,000,000
Funded/(unfunded) status	573,000,000	436,000,000
Defined Benefit Pension Plans and OPEB Plans [Member] | Overfunded Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Funded/(unfunded) status	2,800,000,000	2,600,000,000
Defined Benefit Pension Plans and OPEB Plans [Member] | Underfunded Plans [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Funded/(unfunded) status	612,000,000	621,000,000
Defined Benefit Pension Plans [Member]
Funded status of plan - supplemental information
Unfunded Postretirement Benefit Obligation, U.K. Plan	31,000,000	33,000,000
Defined Benefit Pension Plans, U.S. [Member]
Defined Benefit Plan, Changes in Benefit Obligations and Plan Assets and Funded Status Amounts [Abstract]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of year	(9,043,000,000)	(8,320,000,000)
Defined Benefit Plan, Service Cost	(272,000,000)	(249,000,000)	(230,000,000)
Interest cost on benefit obligations	(466,000,000)	(451,000,000)	(468,000,000)
Plan amendments	0	0
Business combinations	(1,425,000,000)	0
Net gain/(loss)	(864,000,000)	(563,000,000)
Defined Benefit Plan Benefits Paid Benefit Obligation	592,000,000	540,000,000
Foreign exchange impact and other	0	0
Benefit obligation, end of year	(11,478,000,000)	(9,043,000,000)	(8,320,000,000)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	10,472,000,000	10,828,000,000
Actual return on plan assets	1,292,000,000	147,000,000
Firm contributions	31,000,000	37,000,000
Employee contributions	0	0
Benefits paid	(592,000,000)	(540,000,000)
Foreign exchange impact and other	0	0
Fair value of plan assets, end of year	13,012,000,000	10,472,000,000	10,828,000,000
Funded/(unfunded) status	1,534,000,000	1,429,000,000
Accumulated benefit obligation, end of year	(11,447,000,000)	(9,008,000,000)
Defined Benefit Pension Plans, U.S. [Member] | Participation Rights Under Participating Annuity Contracts [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, end of year	418,000,000	426,000,000
Defined Benefit Pension Plans, U.S. [Member] | Accrued Receivables [Member]
Funded status of plan - supplemental information
Defined Benefit Plan Amounts Not Measured At Fair Value	137,000,000	50,000,000
Defined Benefit Pension Plans, U.S. [Member] | Accrued Liabilities [Member]
Funded status of plan - supplemental information
Defined Benefit Plan Amounts Not Measured At Fair Value	310,000,000	245,000,000
Defined Benefit Pension Plans, Non-U.S. [Member]
Defined Benefit Plan, Changes in Benefit Obligations and Plan Assets and Funded Status Amounts [Abstract]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	40,000,000
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of year	(2,829,000,000)	(2,600,000,000)
Defined Benefit Plan, Service Cost	(41,000,000)	(36,000,000)	(31,000,000)
Interest cost on benefit obligations	(126,000,000)	(133,000,000)	(128,000,000)
Plan amendments	6,000,000	0
Business combinations	0	0
Defined Benefit Plan Contributions By Plan Participants Benefit Obligation	(5,000,000)	(5,000,000)
Net gain/(loss)	(244,000,000)	(160,000,000)
Defined Benefit Plan Benefits Paid Benefit Obligation	108,000,000	93,000,000
Foreign exchange impact and other	(112,000,000)	12,000,000
Benefit obligation, end of year	(3,243,000,000)	(2,829,000,000)	(2,600,000,000)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	2,989,000,000	2,647,000,000
Actual return on plan assets	237,000,000	277,000,000
Firm contributions	86,000,000	169,000,000
Employee contributions	5,000,000	5,000,000
Benefits paid	(108,000,000)	(93,000,000)
Foreign exchange impact and other	121,000,000	(16,000,000)
Fair value of plan assets, end of year	3,330,000,000	2,989,000,000	2,647,000,000
Funded/(unfunded) status	87,000,000	160,000,000
Accumulated benefit obligation, end of year	(3,221,000,000)	(2,800,000,000)
Defined Benefit Pension Plans, Non-U.S. [Member] | Contractually Required Payments [Member]
Defined Benefit Plan, Changes in Benefit Obligations and Plan Assets and Funded Status Amounts [Abstract]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	36,000,000
Defined Benefit Pension Plans, Non-U.S. [Member] | Accrued Receivables [Member]
Funded status of plan - supplemental information
Defined Benefit Plan Amounts Not Measured At Fair Value	47,000,000	56,000,000
Defined Benefit Pension Plans, Non-U.S. [Member] | Accrued Liabilities [Member]
Funded status of plan - supplemental information
Defined Benefit Plan Amounts Not Measured At Fair Value	46,000,000	69,000,000
Defined Benefit Pension Plans, Excess Retirement Plan [Member]
Defined Benefit Plan, Changes in Benefit Obligations and Plan Assets and Funded Status Amounts [Abstract]
Defined Benefit Plan Benefit Obligation Excess Retirement Plan	$ 276,000,000	$ 272,000,000