Contingencies (NPM Adjustment Disputes - Settlement with 20 States and Territories and Settlement with New York) (Details) $ in Millions	1 Months Ended						3 Months Ended			12 Months Ended
	Apr. 30, 2020 USD ($)	Apr. 30, 2019 USD ($)	Apr. 30, 2018 USD ($)	Oct. 31, 2017 USD ($) state	Sep. 30, 2013 USD ($) state	Nov. 30, 1998 state	Mar. 31, 2020 USD ($) state claim	Mar. 31, 2019 USD ($)	Mar. 31, 2018 state	Dec. 31, 2018 USD ($) settlement_development	Dec. 31, 2017 USD ($)
Health Care Cost Recovery Actions [Member]
Loss Contingencies [Line Items]
Number of states with settled litigation | state						46
PM USA [Member] | Health Care Cost Recovery Actions [Member]
Loss Contingencies [Line Items]
Loss contingency, reduction to cost of sales								$ 52		$ 209	$ 39
Loss contingency, credits to offset payments							$ 43
Loss contingency, settlement agreement, payment period							9 years
PM USA [Member] | Health Care Cost Recovery Actions [Member] | Settled Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, number of states with settled litigation including New York, subsequent expansion | state							36
Settlement agreements, number | claim							2
Number of states with settled litigation | state							37
PM USA [Member] | Health Care Cost Recovery Actions, 2003-2015 NPM Adjustments [Member] | Settled Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, number of states with settled litigation including New York, subsequent expansion | state				26
​Proceeds from legal settlements				$ 740
Loss contingency, number of settlement developments | settlement_development										2
PM USA [Member] | Health Care Cost Recovery Actions, 2004-2017 [Member] | Settled Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, number of additional states added | state							10		10
Loss contingency, number of additional states extended with settled litigation | state							9
Payments received from litigation settlement		$ 121	$ 68							$ 248
PM USA [Member] | Health Care Cost Recovery Actions, 2003 NPM Adjustment [Member] | Settled Litigation [Member]
Loss Contingencies [Line Items]
Number of states with settled litigation | state					2
PM USA [Member] | Health Care Cost Recovery Actions, 2003 NPM Adjustment [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, number of states | state					15
Number of states without defense | state					6
Loss contingency, number of disputes outstanding | state					2
PM USA [Member] | Health Care Cost Recovery Actions, 2003 NPM Adjustment [Member] | Pending Litigation [Member] | Cost of Sales [Member]
Loss Contingencies [Line Items]
Loss contingency, reduction to cost of sales					$ 74
PM USA [Member] | Health Care Cost Recovery Actions, 2004 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							$ 388
PM USA [Member] | Health Care Cost Recovery Actions, 2005 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							181
PM USA [Member] | Health Care Cost Recovery Actions, 2006 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							154
PM USA [Member] | Health Care Cost Recovery Actions, 2007 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							185
PM USA [Member] | Health Care Cost Recovery Actions, 2008 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							250
PM USA [Member] | Health Care Cost Recovery Actions, 2009 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							211
PM USA [Member] | Health Care Cost Recovery Actions, 2010 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							218
PM USA [Member] | Health Care Cost Recovery Actions, 2011 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							166
PM USA [Member] | Health Care Cost Recovery Actions, 2012 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							214
PM USA [Member] | Health Care Cost Recovery Actions, 2013 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							224
PM USA [Member] | Health Care Cost Recovery Actions, 2014 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							258
PM USA [Member] | Health Care Cost Recovery Actions, 2015 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							313
PM USA [Member] | Health Care Cost Recovery Actions, 2016 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							305
PM USA [Member] | Health Care Cost Recovery Actions, 2017 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							297
PM USA [Member] | Health Care Cost Recovery Actions, 2018 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							340
PM USA [Member] | Health Care Cost Recovery Actions, 2019 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain							441
New York [Member] | PM USA [Member] | Health Care Cost Recovery Actions, Transition Years 2004-2017 [Member] | Settled Litigation [Member]
Loss Contingencies [Line Items]
​Proceeds from legal settlements							$ 317
Maryland, Missouri, New Mexico and Pennsylvania [Member] | PM USA [Member] | Health Care Cost Recovery Actions, 2003 NPM Adjustment [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, number of states remaining | state					4
Subsequent Event [Member] | PM USA [Member] | Health Care Cost Recovery Actions, 2004-2017 [Member] | Settled Litigation [Member]
Loss Contingencies [Line Items]
Payments received from litigation settlement	$ 47