Supplemental Equity and Comprehensive Income Information - Reclass AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Amount Reclassified from Accumulated Other Comprehensive Income
Net of tax	$ (130)	$ (90)	$ (256)	$ (186)
Defined Pension and Postretirement Plans Adjustment
Amount Reclassified from Accumulated Other Comprehensive Income
Transition asset	(1)		(1)	(1)
Prior service benefit	15	16	30	31
Net actuarial loss	173	162	346	325
Curtailments/Settlements	(1)	(1)	(2)	(2)
Total before tax	(160)	(147)	(319)	(297)
Tax effect	39	33	79	75
Net of tax	(121)	(114)	(240)	(222)
Cash Flow Hedging Instruments, Unrealized Gain (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income
Total before tax	(12)	31	(21)	47
Tax effect	3	(7)	5	(11)
Net of tax	(9)	24	(16)	36
Cash Flow Hedging Instruments, Unrealized Gain (Loss) | Foreign currency exchange contracts
Amount Reclassified from Accumulated Other Comprehensive Income
Cost of sales	(10)	33	(17)	51
Cash Flow Hedging Instruments, Unrealized Gain (Loss) | Interest rate contracts
Amount Reclassified from Accumulated Other Comprehensive Income
Interest expense	$ (2)	$ (2)	$ (4)	$ (4)