Contingencies (Health Care Cost Recovery Litigation Narrative) (Details)	1 Months Ended	12 Months Ended
	Nov. 30, 1998 USD ($) state	Dec. 31, 2017 USD ($) case	Dec. 31, 2016 USD ($) case	Dec. 31, 2015 USD ($) case
Cost of Sales [Member]
Loss Contingencies [Line Items]
Loss Contingency, State Settlement Agreements		$ 4,500,000,000	$ 4,600,000,000	$ 4,500,000,000
Health Care Cost Recovery Actions [Member]
Loss Contingencies [Line Items]
Number of cases pending | case		1	1	1
Number of states with settled litigation | state	46
State Settlement Agreements annual payments	$ 9,400,000,000
State settlement agreements attorney fees annual cap	$ 500,000,000
Health Care Cost Recovery Actions [Member] | Canada [Member] | Threatened Litigation [Member]
Loss Contingencies [Line Items]
Number of cases pending | case		10