Derivative Financial instruments and Risk Management- Effect of derivatives designated as hedging instruments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments, Gain (Loss)
Amount of gains (losses) recognized in AOCI	$ 45	$ 5	$ 141	$ (93)
Amount of gain (losses) reclassified from AOCI	(85)	93	(164)	98
Sales and revenues	12,397	9,881	37,173	30,513
Cost of goods sold	8,617	6,919	25,510	21,298
Other income (expense)	225	14	751	265
Designated Derivatives | Cash Flow Hedges
Derivative Instruments, Gain (Loss)
Amount of gains (losses) recognized in AOCI	45	5	141	(93)
Amount of gain (losses) reclassified from AOCI	85	(93)	164	(98)
Machinery, Energy & Transportation
Derivative Instruments, Gain (Loss)
Sales and revenues	11,707	9,228	35,091	28,452
Machinery, Energy & Transportation | Designated Derivatives | Cash Flow Hedges | Foreign exchange contracts
Derivative Instruments, Gain (Loss)
Amount of gains (losses) recognized in AOCI	(47)	66	(40)	(58)
Machinery, Energy & Transportation | Designated Derivatives | Cash Flow Hedges | Foreign exchange contracts | Sales
Derivative Instruments, Gain (Loss)
Amount of gain (losses) reclassified from AOCI	2	(6)	(21)	10
Machinery, Energy & Transportation | Designated Derivatives | Cash Flow Hedges | Foreign exchange contracts | Cost of Sales
Derivative Instruments, Gain (Loss)
Amount of gain (losses) reclassified from AOCI	4	(15)	42	(58)
Machinery, Energy & Transportation | Designated Derivatives | Cash Flow Hedges | Interest rate contracts
Derivative Instruments, Gain (Loss)
Amount of gains (losses) recognized in AOCI		2	7	(14)
Financial Products
Derivative Instruments, Gain (Loss)
Sales and revenues	690	653	2,082	2,061
Financial Products | Designated Derivatives | Cash Flow Hedges | Foreign exchange contracts
Derivative Instruments, Gain (Loss)
Amount of gains (losses) recognized in AOCI	89	(64)	170	2
Financial Products | Designated Derivatives | Cash Flow Hedges | Foreign exchange contracts | Other Nonoperating Income (Expense)
Derivative Instruments, Gain (Loss)
Amount of gain (losses) reclassified from AOCI	87	(63)	167	(35)
Financial Products | Designated Derivatives | Cash Flow Hedges | Foreign exchange contracts | Interest Expense
Derivative Instruments, Gain (Loss)
Amount of gain (losses) reclassified from AOCI	(3)	8	(1)	28
Financial Products | Designated Derivatives | Cash Flow Hedges | Interest rate contracts
Derivative Instruments, Gain (Loss)
Amount of gains (losses) recognized in AOCI	3	1	4	(23)
Financial Products | Designated Derivatives | Cash Flow Hedges | Interest rate contracts | Interest Expense
Derivative Instruments, Gain (Loss)
Amount of gain (losses) reclassified from AOCI	(5)	(16)	(21)	(40)
All other excluding Financial Products
Derivative Instruments, Gain (Loss)
Interest expense excluding Financial Products	$ 114	136	376	384
All other excluding Financial Products | Designated Derivatives | Cash Flow Hedges | Interest rate contracts | Interest Expense
Derivative Instruments, Gain (Loss)
Amount of gain (losses) reclassified from AOCI		$ (1)	$ (2)	$ (3)