Defined Benefit Pension Plan - Fair Value Estimates (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015
Total
Defined benefit pension plan
Fair values	$ 25,767	$ 24,537
Level 1
Defined benefit pension plan
Fair values	531	368
Level 2
Defined benefit pension plan
Fair values	25,236	24,169
Equity securities \| Total
Defined benefit pension plan
Fair values	10,087	9,692
Equity securities \| Level 2
Defined benefit pension plan
Fair values	10,087	9,692
Fixed-income securities \| Total
Defined benefit pension plan
Fair values	15,149	14,477
Fixed-income securities \| Level 2
Defined benefit pension plan
Fair values	15,149	14,477
Cash equivalents \| Total
Defined benefit pension plan
Fair values	531	368
Cash equivalents \| Level 1
Defined benefit pension plan
Fair values	$ 531	$ 368

Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 30
-Section 35
-Paragraph 50
-URI http://asc.fasb.org/extlink&oid=49178875&loc=d3e12355-114930

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant