Asset Impairment, Exit and Implementation Costs (Pre-tax Asset Impairment, Exit and Implementation Costs) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Asset Impairment and Exit Costs	$ 4	$ 120
Implementation Costs	23	2
Total	27	122
Termination and curtailment costs		20
Operating Segments [Member] | Smokeable Products [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment and Exit Costs	1	97
Implementation Costs	5	2
Total	6	99
Operating Segments [Member] | Smokeless Products [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment and Exit Costs	3	13
Implementation Costs	18	0
Total	21	13
Operating Segments [Member] | All Other [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment and Exit Costs	0	5
Implementation Costs	0	0
Total	0	5
General corporate [Member]
Restructuring Cost and Reserve [Line Items]
Asset Impairment and Exit Costs	0	5
Implementation Costs	0	0
Total	0	5
Facilities Consolidation [Member]
Restructuring Cost and Reserve [Line Items]
Total	$ 27		$ 98	$ 71
Productivity Initiative [Member]
Restructuring Cost and Reserve [Line Items]
Total		$ 122