Contingencies (2003-2015 NPM Adjustment Disputes - Settlement with 35 States and Territories and Settlement with New York) (Details) $ in Millions	1 Months Ended		3 Months Ended		12 Months Ended
	Sep. 30, 2013 USD ($) state	Nov. 30, 1998 state	Mar. 31, 2018 USD ($) state	Mar. 31, 2017 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2012 state claims
Loss Contingencies [Line Items]
Loss contingency, reduction to cost of sales			$ 81
Health Care Cost Recovery Actions [Member]
Loss Contingencies [Line Items]
Number of states with settled litigation | state		46
Litigation settlement			1,000	$ 1,100
Health Care Cost Recovery Actions, 2004 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			388
Health Care Cost Recovery Actions, 2005 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			181
Health Care Cost Recovery Actions, 2006 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			154
Health Care Cost Recovery Actions, 2007 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			185
Health Care Cost Recovery Actions, 2008 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			250
Health Care Cost Recovery Actions, 2009 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			211
Health Care Cost Recovery Actions, 2010 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			218
Health Care Cost Recovery Actions, 2011 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			166
Health Care Cost Recovery Actions, 2012 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			214
Health Care Cost Recovery Actions, 2013 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			224
Health Care Cost Recovery Actions, 2014 NPM Adjustment [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			253
Health Care Cost Recovery Actions, 2015 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			300
Health Care Cost Recovery Actions, 2016 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			295
Health Care Cost Recovery Actions, 2017 NPM Adjustments [Member]
Loss Contingencies [Line Items]
Estimate of possible gain			$ 288
PM USA [Member] | Health Care Cost Recovery Actions [Member]
Loss Contingencies [Line Items]
Loss contingency, number of states | state			52
PM USA [Member] | Health Care Cost Recovery Actions [Member] | Settled Litigation [Member]
Loss Contingencies [Line Items]
Number of claims resolved | claims						2
Number of states with settled litigation | state			36
Loss contingency number of states with settled litigation including new york | state						19
Loss contingency, number of states with settled litigation, settlement one | state			35
Litigation settlement					$ 217
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, settlement one | state			26
Litigation settlement			$ 740
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			9
Litigation settlement			$ 81
PM USA [Member] | Health Care Cost Recovery Actions, 2015-2017 Transition Years [Member] | Settled Litigation [Member]
Loss Contingencies [Line Items]
Litigation settlement			$ 13
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 that did not diligently enforcing escrow statutes | state	6
Loss contingency, number of states remaining | state	4
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]
Litigation settlement	$ 74