Retirement Benefits (Summary of changes in the fair value of the plans’ Level 3 assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	$ 1,529	$ 1,507
Purchases	469	279
Sales	(162)	(253)
Unrealized Gain/(Loss)	(222)	(86)
Realized Gain/(Loss)	160	153
Exchange Rate Impact	(98)	(75)
Transfers in/(out) and Other	(2)	4
Fair Value, Asset Value, Ending	1,674	1,529
Private equity/partnerships
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	727	799
Purchases	223	158
Sales	(121)	(185)
Unrealized Gain/(Loss)	(263)	(173)
Realized Gain/(Loss)	159	137
Exchange Rate Impact	(15)	(12)
Transfers in/(out) and Other	0	3
Fair Value, Asset Value, Ending	710	727
Real Estate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	375	312
Purchases	50	97
Sales	(1)	(50)
Unrealized Gain/(Loss)	32	19
Realized Gain/(Loss)	1	16
Exchange Rate Impact	(23)	(19)
Transfers in/(out) and Other	0	0
Fair Value, Asset Value, Ending	434	375
Other Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	239	238
Purchases	47	21
Sales	(13)	(16)
Unrealized Gain/(Loss)	14	18
Realized Gain/(Loss)	0	0
Exchange Rate Impact	(30)	(28)
Transfers in/(out) and Other	0	6
Fair Value, Asset Value, Ending	257	239
Common/Collective trusts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	184	151
Purchases	149	0
Sales	(27)	(1)
Unrealized Gain/(Loss)	(6)	50
Realized Gain/(Loss)	0	0
Exchange Rate Impact	(30)	(16)
Transfers in/(out) and Other	0	0
Fair Value, Asset Value, Ending	270	184
Corporate stocks
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	1	1
Purchases	0	0
Sales	0	0
Unrealized Gain/(Loss)	1	0
Realized Gain/(Loss)	0	0
Exchange Rate Impact	0	0
Transfers in/(out) and Other	0	0
Fair Value, Asset Value, Ending	2	1
Corporate Obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	3	4
Purchases	0	3
Sales	0	(1)
Unrealized Gain/(Loss)	0	0
Realized Gain/(Loss)	0	0
Exchange Rate Impact	0	0
Transfers in/(out) and Other	(2)	(3)
Fair Value, Asset Value, Ending	1	3
Government Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset Value, Beginning	$ 0	2
Purchases		0
Sales		0
Unrealized Gain/(Loss)		0
Realized Gain/(Loss)		0
Exchange Rate Impact		0
Transfers in/(out) and Other		(2)
Fair Value, Asset Value, Ending		$ 0