Benefit Obligations - Amortized in Next Fiscal Year (Details) $ in Millions	12 Months Ended
	Sep. 30, 2015 USD ($)
Pension Benefits - U.S.
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost	$ 1
Recognized net actuarial loss	113
Amortization of prior service cost	114
Pension Benefits - Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost	0
Recognized net actuarial loss	6
Amortization of prior service cost	6
Postretirement Benefits - U.S.
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost	(20)
Recognized net actuarial loss	4
Amortization of prior service cost	$ (16)