Derivatives - Statement of Income Location and Impact of Cash Flow (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Cost of sales
Derivatives in Fair Value Hedging Relationships
Total amounts of income and expense line items presented in the consolidated statement of income in which the effects of cash flow or fair value hedges are recorded	$ 4,313		$ 8,623
Other expense (income), net
Derivatives in Fair Value Hedging Relationships
Total amounts of income and expense line items presented in the consolidated statement of income in which the effects of cash flow or fair value hedges are recorded	256		304
Cash flow hedge
Gain or (loss) on cash flow hedging relationships:
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	20		27
Cash flow hedge | Foreign currency forward/option contracts | Cost of sales
Gain or (loss) on cash flow hedging relationships:
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	21		28
Cash flow hedge | Interest rate swap contracts | Other expense (income), net
Gain or (loss) on cash flow hedging relationships:
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	(1)		(1)
Fair value hedges
Gain or (loss) on fair value hedging relationships:
Hedged items		$ (1)		$ (12)
Fair value hedges | Interest rate swap contracts | Other expense (income), net
Gain or (loss) on fair value hedging relationships:
Hedged items	(7)		(12)
Fair value hedges | Derivatives designated as hedging instruments | Interest rate swap contracts | Other expense (income), net
Gain or (loss) on fair value hedging relationships:
Derivatives designated as hedging instruments	$ 7		$ 12