Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 251	$ 130	$ 788	$ 4,722
Other comprehensive income (loss), net of tax:
Currency translation adjustments, net of tax expense (benefit) of $21 and ($2) for the three months ended September 30, 2017 and 2016, respectively, and $69 and ($12) for the nine months ended September 30, 2017 and 2016, respectively	181	10	530	(16)
Pension and other employee benefits, net of tax expense of $6 and $11 for the three months ended September 30, 2017 and 2016, respectively, and $26 and $32 for the nine months ended September 30, 2017 and 2016, respectively	6	21	44	61
Hedging activities, net of tax benefit of ($2) and zero for the three months ended September 30, 2017 and 2016, respectively, and ($7) and ($5) for the nine months ended September 30, 2017 and 2016, respectively	(6)	1	(16)	(10)
Available-for-sale securities, net of tax expense of zero for the three months ended September 30, 2017 and 2016, and $1 and zero for the nine months ended September 30, 2017 and 2016, respectively	1		4	(4,431)
Total other comprehensive income (loss), net of tax	182	32	562	(4,396)
Comprehensive income	$ 433	$ 162	$ 1,350	$ 326