Retirement Benefit Plans - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Percentage of non-discretionary regular matching contribution of company	100.00%
Percentage of eligible compensation of deferral contribution, minimum	1.00%
Percentage of eligible compensation	80.00%
Percentage of eligible compensation of deferral contribution, maximum	6.00%
Matching contribution expense for defined contribution plan	$ 574	$ 647
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 91

Percentage of deferral participant contribution.

No definition available.

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- Definition

Percentage of eligible compensation of deferral contribution, maximum.

+ References

No definition available.

+ Details

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- Definition

Percentage of eligible compensation of deferral contribution minimum.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of contributions expected to be received by defined benefit plan from employer in next fiscal year following latest fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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Period Type:	instant

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

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- Details

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