Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Line Items]
Cash and Cash Equivalents	$ 139	$ 287	$ 146
Restricted Cash and Cash Equivalents in Other current assets	2,724	850	655
Restricted Cash Equivalents in Other long-term assets	33	31	27
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	2,896	1,168	829	$ 1,017
Trade accounts receivable, net
Accounts receivable	1,693		1,676
Less: allowance for doubtful accounts	(72)		(68)
Trade accounts receivable, net	1,621		1,608
Allowance for doubtful accounts
Beginning balance	68	68
Charges to expenses	7	4
Utilization of allowances	(2)	(5)
Ending balance	72	67
Inventories
Inventory, Finished Goods, Net of Reserves	785		760
Inventory, Work in Process, Net of Reserves	107		100
Inventory, Raw Materials, Net of Reserves	337		306
Inventories	1,228		1,166
Property, plant and equipment, net
Land	96		97
Buildings and improvements	1,112		1,100
Equipment, furniture and fixtures	3,276		3,224
Capital in progress	292		319
Property, plant and equipment	4,777		4,740
Less: accumulated depreciation	2,994		2,958
Property, plant and equipment, net	1,782		1,782
Supplemental Balance Sheet Information
Depreciation expense	69	$ 68
Accrued expenses
Legal reserves, current	527		712
Payroll and related liabilities	530		630
Accrued Rebates, Current	232		229
Business Combination, Contingent Consideration, Liability, Current	159		138
Other	515		538
Accrued expenses	1,963		2,246
Other long-term liabilities
Accrued income taxes	747		739
Legal reserves, noncurrent	172		217
Business Combination, Contingent Consideration, Liability, Noncurrent	236		209
Other Accrued Liabilities, Noncurrent	905		717
Other long-term liabilities	2,059		1,882
Acquisition Related [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Line Items]
Restricted Cash and Cash Equivalents in Other current assets	2,302		$ 0
Non Acquisition Related [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Line Items]
Restricted Cash and Cash Equivalents in Other current assets	$ 422