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DERIVATIVE INSTRUMENTS, CREDIT RISK EXPOSURE (Details) (USD $) | 1 Months Ended | 12 Months Ended |  | 12 Months Ended |  |  |  | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 24, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 External Credit Rating, Investment Grade [Member] | Sep. 30, 2013 External Credit Rating, Non Investment Grade [Member] | Sep. 30, 2013 Internally Rated Investment Grade [Member] | Sep. 30, 2013 Internally Rated Noninvestment Grade [Member] | Sep. 30, 2013 NJRES [Member] | Sep. 30, 2012 NJRES [Member] | Nov. 03, 2011 NJRES [Member] | Sep. 30, 2013 NJRES [Member] CHICAGO MERCANTILE EXCHANGE [Member] | Sep. 30, 2012 NJRES [Member] CHICAGO MERCANTILE EXCHANGE [Member] | Nov. 03, 2011 NJRES [Member] CHICAGO MERCANTILE EXCHANGE [Member] | Nov. 03, 2011 NJRES [Member] INTERCONTINENTAL EXCHANGE [Member]
Credit Risk Exposure [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gross credit exposure |  | $ 228,163,000 |  | $ 189,852,000 | $ 2,947,000 | $ 25,530,000 | $ 9,834,000 |  |  |  |  |  |  |
Derivative, net liability position, aggregate fair value |  | 2,000,000 | 1,600,000 |  |  |  |  |  |  |  |  |  |  |
Additional collateral, aggregate fair value |  | 1,100,000 |  |  |  |  |  |  |  |  |  |  |  |
Restricted broker margin accounts |  | 6,581,000 | 21,929,000 |  |  |  |  |  | 1,200,000 |  |  |  |  |
Other receivables from broker-dealers and clearing organizations | 18,500,000 |  |  |  |  |  |  |  |  | 27,800,000 |  |  | 10,600,000 | 17,200,000
Cash distributions received from claim allowed in liquidation proceedings | 17,100,000 |  |  |  |  |  |  |  |  |  | 859,300 | 8,400,000 |  |
Allowance for doubtful accounts receivable |  |  |  |  |  |  |  | $ 1,400,000 |  |  |  |  |  |

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- Definition The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624258-113959 + Details
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- Definition For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5074-111524 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624258-113959 + Details
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- Definition Amount of right to receive cash and securities on deposit with broker-dealers to demonstrate an intention to complete a purchase (good faith deposit) and collateral deposited by counterparty to cover the credit risk assumed (margin deposit). + References No definition available. + Details
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