FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENT (Details 2) (USD $)	Sep. 30, 2014	Sep. 30, 2013
Supplemental fair value information about long-term fixed-rate debt
Carrying value of long-term fixed-rate debt	$ 80,000,000	$ 195,000,000
Significant Other Observable Inputs (Level 2)
Supplemental fair value information about long-term fixed-rate debt
Fair value of long-term fixed-rate debt	84,300,000	205,400,000
Recurring basis | Total Measure at Fair Value
Assets:
Cash and cash equivalents	360,909,000
Investments	222,300,000
Other current assets	35,450,000
Other assets	2,000,000
Total assets measured at fair value	620,659,000
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash and cash equivalents	360,909,000
Investments	222,300,000
Other current assets	35,200,000
Other assets	2,000,000
Total assets measured at fair value	620,409,000
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Other current assets	250,000
Total assets measured at fair value	$ 250,000