Employee Retirement Plans (Weighted-average assumptions) (Details)	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2010	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011		Sep. 30, 2010	Sep. 30, 2009
Pension Plans [Member]
Weighted-average assumptions:
Discount rate	5.00%	5.50%	4.20%	5.30%	[1]	5.00%	5.50%
Expected return on plan assets			7.75%	8.00%	[1]	8.50%	8.50%
Rate of increase in salary levels			3.25%	3.50%	[1]	3.75%	3.75%
Other Postretirement Benefits [Member]
Weighted-average assumptions:
Discount rate			4.20%	5.30%		5.00%	5.50%
Expected return on plan assets			5.20%	5.50%		5.50%	5.50%
Rate of increase in salary levels			3.25%	3.50%		3.75%	3.75%

[1] The discount rates used during Fiscal 2011 to calculate pension expense were rates of 5.0% through December 31, 2010 (the date of the Pension Plan Merger) and 5.5%