Long Term Debt (Narrative) (Details) (USD $)		12 Months Ended			12 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 U.S. Revolver	Jun. 30, 2013 U.S. Revolver	Sep. 30, 2013 U.S. Revolver Maximum	Sep. 30, 2013 Canadian Revolver	Sep. 30, 2013 Canadian Revolver Maximum	Sep. 30, 2013 Canadian Revolver Minimum	Sep. 30, 2013 Industrial Development Revenue Bonds	Oct. 31, 2001 Industrial Development Revenue Bonds
Line Of Credit Facility [Line Items]
Revolving credit facility			$ 75,000,000.0
Revolving credit interest rate		The interest rate for amounts outstanding under the Amended Credit Agreement for the U.S. Revolver is a floating rate based upon the higher of the Federal Funds Rate plus 0.5%, or the bank’s prime rate.
Basis spread on variable rate		0.50%
Margin				1.75%		1.75%	0.50%
Outstanding letters of credit		20,000,000			100,000
Amount of credit facility remaining borrowing capacity		55,000,000			9,400,000
Credit facility expiration date		Dec. 31, 2016			Feb. 28, 2015
Percentage of voting capital stock pledged as collateral		100.00%
Non-domestic subsidiaries of voting capital stock		66.00%
Revolving credit facility, current borrowing capacity					9,500,000
Borrowings									8,000,000
Reimbursement agreement requires annual redemptions								400,000
Balance in the restricted sinking fund	$ 400,000
Interest rate								0.25%