Contingencies (Details) $ in Millions	9 Months Ended
	Jun. 30, 2015 USD ($)
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	$ 19
Payments and other	(4)
Accruals	2
Ending balance	17
Superfund Sites
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	2
Payments and other	0
Accruals	0
Ending balance	2
Non-Superfund Sites
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	17
Payments and other	(4)
Accruals	2
Ending balance	$ 15