Retirement Benefit Liabilities (Details 1) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension
Service cost	$ 1	$ 1	$ 1	$ 1
Interest cost	17	19	53	59
Assumed return on plan assets	(28)	(26)	(84)	(78)
Amortization of prior service costs	0	0	0	0
Recognized actuarial loss	6	6	20	18
Total expense (income)	(4)	0	(10)	0
Retiree Medical
Service cost	0	0	0	0
Interest cost	5	6	15	19
Assumed return on plan assets	0	0	0	0
Amortization of prior service costs	(1)	(2)	(1)	(6)
Recognized actuarial loss	6	6	16	17
Total expense (income)	$ 10	$ 10	$ 30	$ 30