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Restructuring Actions and Exit Activities - Roll Forward (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	9 Months Ended
	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
2019 Restructuring Actions
Restructuring Reserve Roll Forward
Expenses incurred	$ 148
Non-cash changes		$ (76)
Cash payments		(41)
Adjustments		(14)
Restructuring actions balances, Ending Balance		17	$ 17
2018 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance			84
Expenses incurred				$ 137
Non-cash changes				(12)
Cash payments			(68)	(24)
Adjustments			(3)	(17)
Restructuring actions balances, Ending Balance		13	13	84
Employee-Related \| 2019 Restructuring Actions
Restructuring Reserve Roll Forward
Expenses incurred	108
Non-cash changes		(36)
Cash payments		(41)
Adjustments		(14)
Restructuring actions balances, Ending Balance		17	17
Employee-Related \| 2018 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance			84
Expenses incurred				125
Cash payments			(68)	(24)
Adjustments			(3)	(17)
Restructuring actions balances, Ending Balance		13	$ 13	84
Asset-Related \| 2019 Restructuring Actions
Restructuring Reserve Roll Forward
Expenses incurred	$ 40
Non-cash changes		$ (40)
Asset-Related \| 2018 Restructuring Actions
Restructuring Reserve Roll Forward
Expenses incurred				12
Non-cash changes				$ (12)