Contingencies (Health Care Cost Recovery Litigation) (Details) $ in Millions	1 Months Ended	3 Months Ended
	Nov. 30, 1998 USD ($) state	Mar. 31, 2020 USD ($) case	Mar. 31, 2019 USD ($) manufacture	Apr. 22, 2019 case	Apr. 23, 2018 case
Health Care Cost Recovery Actions [Member]
Loss Contingencies [Line Items]
Number of cases pending | case				1	1
Number of states with settled litigation | state	46
State settlement agreements annual payments	$ 9,400
State settlement agreements attorney fees annual cap	$ 500
Litigation settlement		$ 1,100	$ 900
Threatened Litigation [Member] | Canada [Member] | Health Care Cost Recovery Actions [Member]
Loss Contingencies [Line Items]
Number of cases pending | case		10
Canadian Tobacco Manufacturers [Member] | Canada [Member] | Smoking and Health Class Actions and Aggregated Claims Litigation [Member]
Loss Contingencies [Line Items]
Number of manufacturers | manufacture			3