Retirement Benefit Plans - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018
Retirement Benefits [Abstract]
Employer contributions	$ 403
Plan funded percentage	89.00%
Employer matching contribution percentage of employees' gross pay	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	$ 470	$ 475

Multiemployer Plans, Funded Status, Percent

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Percentage of deferral participant contribution.

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Percentage of eligible compensation of deferral contribution, maximum.

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Percentage of eligible compensation of deferral contribution minimum.

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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Amount of cost for defined contribution plan.

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-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

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

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