DEBT (Details) (USD $)				12 Months Ended									12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Issued to support international operations letter	Sep. 30, 2014 Unsecured revolving credit facility mature May 25, 2017	Sep. 30, 2014 Unsecured revolving credit facility mature May 25, 2017 Maximum	Sep. 30, 2014 Unsecured revolving credit facility mature May 25, 2017 Minimum	Sep. 30, 2014 Unsecured revolving credit facility mature May 25, 2017 London Interbank Offered Rate (LIBOR)	Sep. 30, 2014 Unsecured revolving credit facility mature May 25, 2017 London Interbank Offered Rate (LIBOR) Maximum	Sep. 30, 2014 Unsecured revolving credit facility mature May 25, 2017 London Interbank Offered Rate (LIBOR) Minimum	Sep. 30, 2014 Unsecured revolving credit facility mature May 25, 2017 Letter of credit letter	Sep. 30, 2014 Series D, due August 15, 2014, 6.56%	Sep. 30, 2013 Series D, due August 15, 2014, 6.56%	Sep. 30, 2014 Unsecured senior notes issued July 21, 2009	Sep. 30, 2014 Unsecured senior notes issued July 21, 2009 Maximum	Sep. 30, 2014 Unsecured senior notes issued July 21, 2009 Minimum	Sep. 30, 2014 Due July 21, 2014, 6.10%	Sep. 30, 2013 Due July 21, 2014, 6.10%	Sep. 30, 2014 Due July 21, 2015, 6.10%	Sep. 30, 2013 Due July 21, 2015, 6.10%	Sep. 30, 2014 Due July 21, 2016, 6.10%	Sep. 30, 2013 Due July 21, 2016, 6.10%
Debt
Total long-term debt	$ 80,000,000	$ 195,000,000										$ 75,000,000	$ 80,000,000				$ 40,000,000	$ 40,000,000	$ 40,000,000	$ 40,000,000	$ 40,000,000
Less long-term debt due within one year	40,000,000	115,000,000
Long-term debt	40,000,000	80,000,000
Long-term debt stated interest rate percentage											6.56%	6.56%	6.10%			6.10%	6.10%	6.10%	6.10%	6.10%	6.10%
Annual principal repayments													40,000,000
Funded leverage ratio (as a percent)					50.00%									55.00%
Interest coverage ratio						3.00									2.50
Borrowing amount				300,000,000
Available borrowing capacity to use for letters of credit										100,000,000
LIBOR spread on borrowings (as a percent)							1.125%	1.75%	1.125%
Commitment fee (as a percent)				0.15%	0.35%	0.15%
Borrowing amount outstanding				0
Number of letters of credit outstanding			2							3
Letters of credit outstanding/issued			12,000,000							34,200,000
Available borrowing capacity excluding letters of credit transaction				$ 265,800,000