Retirement Benefit Liabilities (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Pension
Interest cost	$ 18	$ 20	$ 36	$ 40
Assumed return on plan assets	(28)	(26)	(56)	(52)
Amortization of prior service costs	0	0	0	0
Recognized actuarial loss	7	6	14	12
Total expense (income)	(3)	0	(6)	0
Retiree Medical
Interest cost	5	7	10	13
Assumed return on plan assets	0	0	0	0
Amortization of prior service costs	0	(2)	0	(4)
Recognized actuarial loss	5	5	10	11
Total expense (income)	$ 10	$ 10	$ 20	$ 20