Contingencies (Judgments Paid and Provisions for Tobacco and Health Litigation) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended			195 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020
Loss Contingency Accrual [Roll Forward]
Accrued liability for tobacco and health litigation items at beginning of period				$ 14				$ 112	$ 14	$ 112	$ 106
Provision related to litigation recorded	$ 7	$ 34	$ 18	$ 24	$ 29	$ 3	$ 28	$ 17
Payments									(88)	(175)	(125)
Accrued liability for tobacco and health litigation items at end of period	9				$ 14				9	14	112	$ 9
Related Interest Costs [Member]
Loss Contingency Accrual [Roll Forward]
Provision related to litigation recorded									4	5	18
Tobacco and Health Judgment [Member]
Loss Contingencies [Line Items]
Judgments paid (approximately)												805
Litigation settlement interest (approximately)												218
Tobacco and Health Judgment [Member] | Tobacco and Health Litigation [Member]
Loss Contingency Accrual [Roll Forward]
Provision related to litigation recorded									79	$ 72	$ 113
Engle Progeny Cases [Member]
Loss Contingencies [Line Items]
Judgments paid (approximately)												365
Litigation settlement interest (approximately)												56
Assets [Member] | Pending Litigation [Member] | PM USA [Member]
Loss Contingencies [Line Items]
Security posted for appeal of judgments	$ 61								$ 61			$ 61