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Employee Benefits (Details) $ in Thousands | 1 Months Ended | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Mar. 31, 2017 USD ($) | Sep. 30, 2017 USD ($) shares | Sep. 30, 2016 USD ($) | Sep. 30, 2017 USD ($) Employee shares | Sep. 30, 2016 USD ($)
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |
Number of former union employees not covered under plan | Employee |  |  |  | 24 |
Postretirement Benefits [Member] |  |  |  |  |
Net Periodic benefit costs related to retirement plans [Abstract] |  |  |  |  |
Service cost |  | $ 0 | $ 0 | $ 0 | $ 0
Interest cost |  | 2 | 4 | 6 | 10
Amortization of prior service cost |  | 0 | (14) | 0 | (41)
Actuarial net loss |  | (165) | 194 | (496) | 584
Net periodic benefit cost (credit) |  | $ (163) | $ 184 | $ (490) | $ 553
Supplemental Executive Retirement Plan [Member] |  |  |  |  |
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract] |  |  |  |  |
Employer discretionary contribution amount | $ 300 |  |  |  |
Employee Stock Ownership Plan and Trust (ESOP) [Member] |  |  |  |  |
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] |  |  |  |  |
Additional shares contributed to ESOP (in shares) | shares |  |  |  | 43,300 |
Shares released from trust (in shares) | shares |  | 43,300 |  | 43,300 |
Total remaining balance of shares in the ESOP (in shares) | shares |  | 200 |  | 200 |

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- Definition Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan. + 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 (a)(4) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. + 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 (h)(5) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + 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 cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. + 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 (h)(1) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Sum of the allocated, committed-to-be-released and suspense shares of the entity held by the plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 40 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=65895303&loc=d3e17540-113929 + Details
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