Restructuring Actions - Roll Forward (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended			12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
2020 Restructuring Actions | Other Restructuring
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance		$ 58
Non-cash changes		(23)
Cash Payments		(2)
Restructuring Reserve, Accrual Adjustment		(9)
Restructuring actions balances, Ending Balance	$ 24	24			$ 24
2019 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance			$ 282		140
Non-cash changes			(76)
Cash Payments			(52)		(51)
Restructuring Reserve, Accrual Adjustment			(14)		(59)
Restructuring actions balances, Ending Balance	30	30	140		30	$ 140
2018 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance				$ 137	3	84
Non-cash changes				(12)
Cash Payments				(24)		(76)
Restructuring Reserve, Accrual Adjustment				(17)		(5)
Restructuring actions balances, Ending Balance			3	84		3
Employee-Related | 2020 Restructuring Actions | Other Restructuring
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance		35
Cash Payments		(2)
Restructuring Reserve, Accrual Adjustment		(9)
Restructuring actions balances, Ending Balance	24	24			24
Employee-Related | 2019 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance			242		140
Non-cash changes			(36)
Cash Payments			(52)		(51)
Restructuring Reserve, Accrual Adjustment			(14)		(59)
Restructuring actions balances, Ending Balance	30	30	140		30	140
Employee-Related | 2018 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance				125	3	84
Cash Payments				(24)		(76)
Restructuring Reserve, Accrual Adjustment				(17)		(5)
Restructuring actions balances, Ending Balance			3	84		$ 3
Asset-Related | 2020 Restructuring Actions | Other Restructuring
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance		23
Non-cash changes		(23)
Asset-Related | 2019 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance			40
Non-cash changes			$ (40)
Asset-Related | 2018 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance				12
Non-cash changes				$ (12)
Operational/Marketing Capability Restructuring | 2020 Restructuring Actions
Restructuring Reserve Roll Forward
Expenses incurred	137
Non-cash changes	(36)
Restructuring actions balances, Ending Balance	101	101			101
Operational/Marketing Capability Restructuring | Employee-Related | 2020 Restructuring Actions
Restructuring Reserve Roll Forward
Expenses incurred	101
Restructuring actions balances, Ending Balance	101	101			101
Operational/Marketing Capability Restructuring | Asset-Related and Other | 2020 Restructuring Actions
Restructuring Reserve Roll Forward
Expenses incurred	36
Non-cash changes	(36)
Drug delivery business | 2020 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance		55
Non-cash changes		(14)
Cash Payments		(14)
Restructuring Reserve, Accrual Adjustment		(3)
Restructuring actions balances, Ending Balance	24	24			24
Drug delivery business | Employee-Related | 2020 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance		32
Cash Payments		(14)
Restructuring Reserve, Accrual Adjustment		(3)
Restructuring actions balances, Ending Balance	15	15			15
Drug delivery business | Asset-Related and Other | 2020 Restructuring Actions
Restructuring Reserve Roll Forward
Restructuring actions balances, Beginning Balance		23
Non-cash changes		(14)
Restructuring actions balances, Ending Balance	$ 9	$ 9			$ 9