FAIR VALUE OF FINANCIAL INSTRUMENTS, Schedule of Fair Value of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 178,459	$ 302,546
Auction rate securities (ARS)	7,991	8,041
Other long-term investments	1,082	827
Total	187,532	311,414
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	178,459	302,546
Auction rate securities (ARS)	0	0
Other long-term investments	1,082	827
Total	179,541	303,373
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Auction rate securities (ARS)	0	0
Other long-term investments	0	0
Total	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Auction rate securities (ARS)	7,991	8,041
Other long-term investments	0	0
Total	$ 7,991	$ 8,041