Contingencies (Number of Tobacco Related Cases Pertaining to Combustible Products Pending Against Us and/or Our Subsidiaries or Indemnitees) (Details) - Combustible Products [Member] - litigation_case	Jul. 23, 2019	Jul. 24, 2018	Jul. 25, 2017
Individual Smoking And Health Cases [Member]
Loss Contingencies [Line Items]
Cases brought against PM		65	68
Smoking And Health Class Actions [Member]
Loss Contingencies [Line Items]
Cases brought against PM		11	11
Health Care Cost Recovery Actions [Member]
Loss Contingencies [Line Items]
Cases brought against PM		16	16
Label Related Class Action [Member]
Loss Contingencies [Line Items]
Cases brought against PM		1	0
Individual Label Related Cases [Member]
Loss Contingencies [Line Items]
Cases brought against PM		1	1
Public Civil Actions [Member]
Loss Contingencies [Line Items]
Cases brought against PM		2	2
Subsequent Event [Member] | Individual Smoking And Health Cases [Member]
Loss Contingencies [Line Items]
Cases brought against PM	52
Subsequent Event [Member] | Smoking And Health Class Actions [Member]
Loss Contingencies [Line Items]
Cases brought against PM	10
Subsequent Event [Member] | Health Care Cost Recovery Actions [Member]
Loss Contingencies [Line Items]
Cases brought against PM	17
Subsequent Event [Member] | Label Related Class Action [Member]
Loss Contingencies [Line Items]
Cases brought against PM	1
Subsequent Event [Member] | Individual Label Related Cases [Member]
Loss Contingencies [Line Items]
Cases brought against PM	6
Subsequent Event [Member] | Public Civil Actions [Member]
Loss Contingencies [Line Items]
Cases brought against PM	2