Condensed Financial Information of Registrant (Parent Company) (Details)	12 Months Ended
	Sep. 30, 2015 USD ($)
Parent Company
Guarantee Obligations
Surety bonds indemnified	$ 71,100,000
Maximum amount authorized to guarantee obligations to suppliers and customers	500,000,000
Current carrying value	445,300,000
Flaga
Guarantee Obligations
Amount of floating to fixed rate interest rate swaps at Flaga	$ 1,200,000