Retirement Benefits (Summary of changes in the fair value of the plans’ Level 3 assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	$ 1,245	$ 1,122
Purchases	311	301
Sales	(251)	(219)
Unrealized Gain/(Loss)	(46)	54
Realized Gain/(Loss)	61	23
Exchange Rate Impact	10	(36)
Transfers in/(out) and Other	(1)	0
Fair Value, Asset Value, Ending	1,329	1,245
Private equity/partnerships [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	746	637
Purchases	119	138
Sales	(80)	(54)
Unrealized Gain/(Loss)	(83)	15
Realized Gain/(Loss)	70	22
Exchange Rate Impact	7	(12)
Transfers in/(out) and Other	0	0
Fair Value, Asset Value, Ending	779	746
Real estate [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	293	269
Purchases	0	0
Sales	0	0
Unrealized Gain/(Loss)	22	34
Realized Gain/(Loss)	(1)	0
Exchange Rate Impact	5	(10)
Transfers in/(out) and Other	0	0
Fair Value, Asset Value, Ending	319	293
Other investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	177	180
Purchases	32	19
Sales	(13)	(16)
Unrealized Gain/(Loss)	6	3
Realized Gain/(Loss)	2	1
Exchange Rate Impact	(2)	(14)
Transfers in/(out) and Other	0	4
Fair Value, Asset Value, Ending	202	177
Insurance group annuity contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	20	17
Purchases	151	141
Sales	(150)	(140)
Unrealized Gain/(Loss)	8	2
Realized Gain/(Loss)	(9)	0
Exchange Rate Impact	0	0
Transfers in/(out) and Other	0	0
Fair Value, Asset Value, Ending	20	20
Corporate stocks [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	1	11
Purchases	8	1
Sales	0	(4)
Unrealized Gain/(Loss)	(1)	(3)
Realized Gain/(Loss)	0	1
Exchange Rate Impact	0	0
Transfers in/(out) and Other	0	(5)
Fair Value, Asset Value, Ending	8	1
Corporate Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	8	5
Purchases	1	2
Sales	(8)	(2)
Unrealized Gain/(Loss)	2	3
Realized Gain/(Loss)	(1)	(1)
Exchange Rate Impact	0	0
Transfers in/(out) and Other	(1)	1
Fair Value, Asset Value, Ending	1	8
Government Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning		3
Purchases		0
Sales		(3)
Unrealized Gain/(Loss)		0
Realized Gain/(Loss)		0
Exchange Rate Impact		0
Transfers in/(out) and Other		0
Fair Value, Asset Value, Ending		$ 0