FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENT (Details) (USD $)	12 Months Ended				12 Months Ended
	Sep. 30, 2013 Partnership	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2010	Sep. 30, 2013 Equity securities	Sep. 30, 2012 Equity securities	Sep. 30, 2011 Equity securities
Available-for-sale securities
Cost					$ 68,434,000	$ 129,183,000
Gross unrealized gains					237,214,000	304,396,000
Estimated fair value					305,648,000	433,579,000
Equity available-for-sale securities sold, fair value					214,100,000	0	0
Total gross realized gain on such sales of available-for-sale securities					153,400,000
Limited Liability Partnerships
Number of limited partnerships that entity sold shares of the partnership	3
Investments in limited partnerships sold, fair value		3,900,000
Investments in limited partnerships, at carried cost			9,400,000	3,000,000
Realized gain on sale of investment securities	8,800,000	900,000
Investments in limited partnerships, at fair value			18,000,000
Non-qualified Supplemental Savings Plan
Assets held in Non-qualified Supplement Savings Plan, at Fair Value	$ 10,500,000		$ 8,200,000