Consolidated Statements of Shareholders' Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Tax on foreign currency translation	$ (2)	$ (52)	$ (46)
Tax on foreign currency translation reclassification adjustment recognized in income	0	0	0
Tax on amortization of prior service cost and unrecognized gains and losses included in total benefit cost	33	34	36
Tax on increase in net actuarial losses	(53)	(19)	(135)
Tax on immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	0	67	13
Tax on deferred derivative gains	4	3	1
Tax on deferred derivative gains reclassification adjustment for amounts recognized in income	(1)	(3)	(1)
Tax on unrealized investment gains	0	(2)	1
Tax on unrealized investment gains reclassification adjustment recognized in income	$ 0	$ 2	$ 0
Total
Common treasury shares (in shares)	26,866,893,000,000	11,445,445,000,000	8,979,927,000,000	3,136,663,000,000
Tax on foreign currency translation	$ (2)	$ (52)	$ (46)
Tax on foreign currency translation reclassification adjustment recognized in income		0	0
Tax on amortization of prior service cost and unrecognized gains and losses included in total benefit cost	33	34	36
Tax on increase in net actuarial losses	(53)	(19)	(129)
Tax on immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	0	67	13
Tax on deferred derivative gains	4	3	1
Tax on deferred derivative gains reclassification adjustment for amounts recognized in income	$ (1)	(3)
Tax on unrealized investment gains		(2)	1
Tax on unrealized investment gains reclassification adjustment recognized in income		2
Tax on deconsolidation of subsidiary		0
Minority Shareholders' Equity - Redeemable
Tax on foreign currency translation		0	0
Tax on amortization of prior service cost and unrecognized gains and losses included in total benefit cost		0	0
Tax on increase in net actuarial losses		0	6
Tax on immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures		0	0
Tax on prior service credit from plan amendments		0	0
Tax on deferred derivative gains		0	0
Tax on deferred derivative gains reclassification adjustment for amounts recognized in income		$ 0	$ 1