Shareholders' Equity - AOCI Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Loss
Accumulated other comprehensive income (loss) components which were reclassified to the Consolidated Statement of Operations
Total reclassifications for the period	$ 340	$ 366
Defined benefit pension plan
Accumulated other comprehensive income (loss) components which were reclassified to the Consolidated Statement of Operations
Reclassifications for the period, tax	(121)	(209)
Amortization of net actuarial loss on defined benefit pension plan \| General and Administrative
Accumulated other comprehensive income (loss) components which were reclassified to the Consolidated Statement of Operations
Reclassifications for the period, before tax	$ 461	$ 575

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.

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669686-108580

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
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-Section 55
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=84158357&loc=d3e1436-108581

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 20
-Section 45
-Paragraph 11
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-URI http://asc.fasb.org/extlink&oid=79507043&loc=d3e39076-109324

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