Supplemental Equity and Comprehensive Income Information - Reclass AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Amount Reclassified from Accumulated Other Comprehensive Income
Net of tax	$ (126)	$ (96)
Defined Pension and Postretirement Plans Adjustment
Amount Reclassified from Accumulated Other Comprehensive Income
Transition asset		(1)
Prior service benefit	15	15
Net actuarial loss	(173)	(163)
Curtailments/Settlements	(1)	(1)
Total before tax	(159)	(150)
Tax effect	40	42
Net of tax	(119)	(108)
Cash Flow Hedging Instruments, Unrealized Gain (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income
Total before tax	(9)	16
Tax effect	2	(4)
Net of tax	(7)	12
Cash Flow Hedging Instruments, Unrealized Gain (Loss) | Foreign currency exchange contracts
Amount Reclassified from Accumulated Other Comprehensive Income
Cost of sales	(7)	18
Cash Flow Hedging Instruments, Unrealized Gain (Loss) | Interest rate contracts
Amount Reclassified from Accumulated Other Comprehensive Income
Interest expense	$ (2)	$ (2)