Accumulated Other Comprehensive Income (Details 2) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Pension and post retirement [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of deferred actuarial losses, tax	$ (18)	$ (14)
Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Deferred cash flow hedging gains (losses), tax	(4)	2
Reclass of deferred cash flow hedging (losses), tax	$ (5)	$ (5)