Retirement Benefits (Reconciliation of Net Actuarial Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
U.S. Pension Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Effect of curtailment	$ (98)	$ 0
Other	0	0
Non-U.S. Pension Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Effect of curtailment	(7)	8
Other	0	24
U.S. Postretirement Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Effect of curtailment	0	0
Other	(1)	(12)
Non-U.S. Postretirement Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Effect of curtailment	0	0
Other	0	0
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) | U.S. Pension Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Beginning balance	(1,754)	(1,749)
Recognized as component of net periodic benefit cost	74	146
Effect of curtailment	(98)	0
Other	0	0
Liability experience	(160)	392
Asset experience	22	(543)
Total amount recognized as change in plan assets and benefit obligations	(40)	(151)
Ending balance, December 31	(1,720)	(1,754)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) | Non-U.S. Pension Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Beginning balance	(2,887)	(3,215)
Recognized as component of net periodic benefit cost	94	125
Effect of settlement	0	2
Liability experience	(1,966)	432
Asset experience	1,254	(417)
Plan amendments	0	(20)
Effect of curtailment	3	0
Total amount recognized as change in plan assets and benefit obligations	(709)	(5)
Exchange rate adjustments	421	206
Ending balance, December 31	(3,081)	(2,887)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) | U.S. Postretirement Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Beginning balance	13	2
Recognized as component of net periodic benefit cost	(2)	(2)
Effect of curtailment	0	0
Other	0	(8)
Liability experience	0	5
Asset experience	0	0
Total amount recognized as change in plan assets and benefit obligations	0	5
Ending balance, December 31	11	13
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) | Non-U.S. Postretirement Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Beginning balance	(6)	(14)
Recognized as component of net periodic benefit cost	0	1
Effect of settlement	0	0
Liability experience	(5)	6
Asset experience	0	0
Plan amendments	0	0
Effect of curtailment	0	0
Total amount recognized as change in plan assets and benefit obligations	(5)	6
Exchange rate adjustments	0	1
Ending balance, December 31	$ (11)	$ (6)