FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENT (Details 2) (USD $)	Sep. 30, 2013	Sep. 30, 2012
Supplemental fair value information about long-term fixed-rate debt
Carrying value of long-term fixed-rate debt	$ 195,000,000	$ 235,000,000
Significant Other Observable Inputs (Level 2)
Supplemental fair value information about long-term fixed-rate debt
Carrying value of long-term fixed-rate debt	195,000,000	235,000,000
Fair value of long-term fixed-rate debt	205,400,000	252,700,000
Recurring basis | Total Measure at Fair Value
Assets
Cash and cash equivalents	447,868,000
Investments	305,648,000
Other current assets	27,396,000
Other assets	2,000,000
Total assets measured at fair value	782,912,000
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Cash and cash equivalents	447,868,000
Investments	305,648,000
Other current assets	27,146,000
Other assets	2,000,000
Total assets measured at fair value	782,662,000
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets
Other current assets	250,000
Total assets measured at fair value	$ 250,000