Contingencies (Judgments Paid and Provisions for Tobacco and Health Litigation) (Details) $ in Millions	3 Months Ended		174 Months Ended
	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2019 USD ($)
Loss Contingency Accrual [Roll Forward]
Accrued liability for tobacco and health litigation items at beginning of period	$ 112	$ 106
Payments	(109)	(23)
Accrued liability for tobacco and health litigation items at end of period	20	111	$ 20
Interest Expense Related To Litigation [Member]
Loss Contingency Accrual [Roll Forward]
Provision related to litigation recorded	2	4
Tobacco and Health Judgment [Member]
Loss Contingencies [Line Items]
Judgments paid (approximately)			668
Litigation settlement interest expense (income)			211
Tobacco and Health Judgment [Member] | Litigation Cases Results [Member]
Loss Contingency Accrual [Roll Forward]
Provision related to litigation recorded	15	$ 24
Engle Progeny Cases [Member]
Loss Contingencies [Line Items]
Judgments paid (approximately)			276
Litigation settlement interest expense (income)			49
Assets [Member] | Pending Litigation [Member] | PM USA [Member]
Loss Contingency Accrual [Roll Forward]
Security posted for appeal of judgments	$ 103		$ 103