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Summary of Significant Accounting - Future Undiscounted Losses (Details) - USD ($) $ in Thousands | 12 Months Ended
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Sep. 30, 2017 | Sep. 30, 2016
Summary Of Significant Accounting Policies [Abstract] |  |
EstimatedUndiscountedUltimateLossesInNextTwelveMonths | $ 1,888 |
EstimatedUndiscountedUltimateLossesInYearTwo | 1,124 |
EstimatedUndiscountedUltimateLossesInYearThree | 778 |
EstimatedUndiscountedUltimateLossesInYearFour | 416 |
EstimatedUndiscountedUltimateLossesInYearFive | 193 |
EstimatedUndiscountedUltimateLossesThereafter | 907 |
Loss Contingency, Undiscounted Amount of Insurance-related Assessment Liability | $ 5,306 | $ 5,223

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- Definition The liability as of the balance sheet date representing required funding mandated by statute or regulatory authority that is related directly or indirectly to underwriting activities, including pools for self-insurance and excluding premium taxes and income taxes. The funds derived from the assessments generally enable a government guarantor to pay insurance claims in the event that the underwriting insurer is insolvent or otherwise unable to meet its payment obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 405 -SubTopic 30 -Section 15 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=51828112&loc=d3e23169-109297 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 405 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6392405&loc=d3e24119-109301 + Details
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