Benefit Plans (Movements in Other Comprehensive Earnings/Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Amortization:
Net loss	$ 214	$ 296	$ 187
Prior service cost/credit	(34)	(32)	(33)
Other expense (income):
Net loss, other expense (income)	9	8
Prior service cost/credit	(11)
Deferred income taxes	(65)	(105)	(60)
Amounts reclassified to net earnings as components of net periodic benefit cost	113	167	94
Other movements during the year:
Net loss, Other movements during the year	(259)	(223)	(1,411)
Prior service cost/credit, Other movements during the year	12	0
Deferred income taxes, Other movements during the year	96	86	550
Other movements	(151)	(137)	(861)
Total movements in other comprehensive earnings/losses	(38)	30	(767)
Pension [Member]
Amortization:
Net loss	171	234	147
Prior service cost/credit	5	7	10
Other expense (income):
Net loss, other expense (income)	9	8
Prior service cost/credit	2
Deferred income taxes	(69)	(96)	(61)
Amounts reclassified to net earnings as components of net periodic benefit cost	118	153	96
Other movements during the year:
Net loss, Other movements during the year	(232)	(410)	(1,093)
Prior service cost/credit, Other movements during the year	(4)	(6)
Deferred income taxes, Other movements during the year	92	160	425
Other movements	(144)	(256)	(668)
Total movements in other comprehensive earnings/losses	(26)	(103)	(572)
Postretirement Benefit Plan [Member]
Amortization:
Net loss	25	43	22
Prior service cost/credit	(39)	(39)	(43)
Other expense (income):
Net loss, other expense (income)	0	0
Prior service cost/credit	(13)
Deferred income taxes	11	(2)	8
Amounts reclassified to net earnings as components of net periodic benefit cost	(16)	2	(13)
Other movements during the year:
Net loss, Other movements during the year	(18)	192	(306)
Prior service cost/credit, Other movements during the year	16	6
Deferred income taxes, Other movements during the year	1	(75)	120
Other movements	(1)	123	(186)
Total movements in other comprehensive earnings/losses	(17)	125	(199)
Postemployment Benefit Plans [Member]
Amortization:
Net loss	18	19	18
Prior service cost/credit	0	0	0
Other expense (income):
Net loss, other expense (income)	0	0
Prior service cost/credit	0
Deferred income taxes	(7)	(7)	(7)
Amounts reclassified to net earnings as components of net periodic benefit cost	11	12	11
Other movements during the year:
Net loss, Other movements during the year	(9)	(5)	(12)
Prior service cost/credit, Other movements during the year	0	0
Deferred income taxes, Other movements during the year	3	1	5
Other movements	(6)	(4)	(7)
Total movements in other comprehensive earnings/losses	$ 5	$ 8	$ 4