Benefit Plans Contributions (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2013 Supplemental Employee Retirement Plans, Defined Benefit	Sep. 30, 2012 Supplemental Employee Retirement Plans, Defined Benefit	Sep. 30, 2013 Other Post-retirement Benefits	Sep. 30, 2012 Other Post-retirement Benefits	Sep. 30, 2011 Other Post-retirement Benefits	Sep. 30, 2012 Pension Benefits	Sep. 30, 2011 Pension Benefits	Sep. 30, 2011 Other Pension Plans, Defined Benefit	Sep. 30, 2009 Other Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Employer contributions	$ 6	$ 8	$ 38	$ 41	$ 38	$ 8	$ 274	$ 270	$ 1,000