Retirement Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Compensation and Retirement Disclosure [Abstract]
Voluntary Contribution To Qualified Pension Plan Trust				$ 300
Pension Benefits [Member]
Components of net periodic benefit cost
Service cost	22.9	17.8	69.0	53.8
Interest cost	40.0	41.7	120.2	125.6
Expected return on plan assets	(56.5)	(56.8)	(169.7)	(171.0)
Amortization:
Prior service credit	(0.6)	(0.6)	(1.9)	(1.8)
Net actuarial loss	36.1	23.6	108.5	71.0
Net periodic benefit cost	41.9	25.7	126.1	77.6
Other Postretirement Benefits [Member]
Components of net periodic benefit cost
Service cost	0.6	0.6	1.8	1.7
Interest cost	1.6	1.8	4.7	5.4
Amortization:
Prior service credit	(2.7)	(2.6)	(8.1)	(7.9)
Net actuarial loss	1.1	0.6	3.3	1.8
Net periodic benefit cost	$ 0.6	$ 0.4	$ 1.7	$ 1.0