Contingencies (NPM Adjustment Disputes - Settlement with 20 States and Territories and Settlement with New York) (Details) $ in Millions	1 Months Ended					3 Months Ended		9 Months Ended	12 Months Ended
	Apr. 30, 2019 USD ($)	Apr. 30, 2018 USD ($)	Oct. 31, 2017 USD ($) state	Sep. 30, 2013 USD ($) state	Nov. 30, 1998 state	Mar. 31, 2019 USD ($)	Mar. 31, 2018 state	Sep. 30, 2019 USD ($) state claim	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2018 settlement_development
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
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									2		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
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								299
PM USA [Member] | Health Care Cost Recovery Actions, 2016 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain								292
PM USA [Member] | Health Care Cost Recovery Actions, 2017 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain								285
PM USA [Member] | Health Care Cost Recovery Actions, 2018 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain								332
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								$ 265
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