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CONCENTRATIONS OF CREDIT RISK (Details) $ in Millions | 3 Months Ended
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Dec. 31, 2017 USD ($) subsegment counterparty
Concentration Risk [Line Items] |
Number of groups with potential to affect overall exposure | subsegment | 3
Number of large counterparties for which credit risk is disclosed | counterparty | 5
Number of counterparties with investment-grade rating | counterparty | 3
Number of counterparties with non-investment grade rating | counterparty | 2
Energy Producers And Their Affiliates |
Concentration Risk [Line Items] |
Accounts receivable | $ 19.4
Net receivable amount | 15.3
Utility Companies And Their Affiliates |
Concentration Risk [Line Items] |
Accounts receivable | 47.5
Net receivable amount | 45.4
Largest Counterparties |
Concentration Risk [Line Items] |
Accounts receivable | 26.7
Net receivable amount | $ 23.9

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- Definition This item represents disclosure of all significant concentrations of credit risk or market risk arising from the subject financial instrument (as defined), whether from an individual counterparty or groups of counterparties. + References Reference 1: 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(3)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(5)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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