Retirement Benefits Plans - Benefits Expense (Details 5) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
United States pension benefit expense
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	$ 128	$ 115	$ 93
Interest cost	147	134	132
Expected return on plan assets	(226)	(183)	(164)
Amortization	133	118	75
Benefit plans	182	184	136
Curtailment loss	0	0	0
Settlement loss	53	20	17
Total expense	235	204	153
Non-United States pension benefit expense [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	62	50	48
Interest cost	80	77	78
Expected return on plan assets	(85)	(77)	(70)
Amortization	27	15	13
Benefit plans	84	65	69
Curtailment loss	1	1	1
Settlement loss	1	3	4
Total expense	86	69	74
Other postretirement benefits expense [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	20	17	15
Interest cost	35	38	41
Expected return on plan assets	(6)	(6)	0
Amortization	14	13	12
Benefit plans	63	62	68
Curtailment loss	0	0	0
Settlement loss	0	0	0
Total expense	$ 63	$ 62	$ 68