Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Tax on foreign currency translation	$ 4	$ (10)	$ 39
Defined benefit plans:
Tax on amortization of prior service cost and unrecognized gains and losses included in total benefit cost	33	34	40
Tax on increase in net actuarial losses	(42)	1	(37)
Tax on immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	2	5	14
Tax on prior service cost from plan amendments	1	(3)	(2)
Tax effect of deferred derivative gains	0	3	(8)
Tax effect of reclassification adjustment for amounts recognized in income	$ 0	$ 0	$ 1