Retirement Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Retirement Benefits (Textual) [Abstract]
Voluntary contribution to qualified pension plan trust	$ 300
Pension Benefits [Member]
Components of net periodic benefit cost
Service cost	17.9	17.4
Interest cost	41.9	40.7
Expected return on plan assets	(57.0)	(50.7)
Amortization:
Prior service credit	(0.6)	(0.5)
Net actuarial loss	23.7	15.9
Net periodic benefit cost	25.9	22.8
Other Postretirement Benefits [Member]
Components of net periodic benefit cost
Service cost	0.5	0.9
Interest cost	1.8	2.5
Amortization:
Prior service credit	(2.6)	(2.6)
Net actuarial loss	0.6	1.6
Net periodic benefit cost	$ 0.3	$ 2.4