FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
	Mar. 31, 2012	Jun. 30, 2012	Jun. 30, 2012 Level 1 [Member]	Sep. 30, 2011 Level 1 [Member]	Jun. 30, 2012 Level 2 [Member]	Sep. 30, 2011 Level 2 [Member]	Jun. 30, 2012 Level 3 [Member]	Sep. 30, 2011 Level 3 [Member]	Jun. 30, 2012 Fair Value, Measurements, Recurring [Member]	Sep. 30, 2011 Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents			$ 166,896	$ 302,546	$ 0	$ 0	$ 0	$ 0	$ 166,896	$ 302,546
Auction rate securities (ARS)			0	0	0	0	7,991	8,041	7,991	8,041
Other long-term investments			1,020	827	0	0	0	0	1,020	827
Total			167,916	303,373	0	0	7,991	8,041	175,907	311,414
Other long-term investment, Supplemental Employee Retirement Plan (SERP)		1,020
Corresponding SERP liability		1,020
Beginning balance		8,041
Net sales of ARS		(50)
Ending balance		7,991
Auction rate securities (ARS) par value		8,225
Number of impaired auction rate securities (ARS)		1
Fair value of impaired security		3,041
Par value of impaired security		3,275
Impairment amount of impaired security		234
Monetized par value of impaired security	$ 50