Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning of period			$ (13,256)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	$ 7	$ (158)	(19)	$ (14)
Total other comprehensive income adjustments	518	551	834	1,167
Accumulated other comprehensive loss, end of period	(12,422)		(12,422)
Accumulated Net Unrealized Investment Gain (Loss) [Member] \| Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning of period	(3)	225	23	81
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	7	(158)	(19)	(14)
Amortization - Pension and postretirement benefits	0	0	0	0
Total other comprehensive income adjustments	7	(158)	(19)	(14)
Accumulated other comprehensive loss, end of period	4	67	4	67
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning of period	(12,937)	(12,886)	(13,279)	(13,358)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	0	0	0	0
Amortization - Pension and postretirement benefits	511	709	853	1,181
Total other comprehensive income adjustments	511	709	853	1,181
Accumulated other comprehensive loss, end of period	(12,426)	(12,177)	(12,426)	(12,177)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning of period	(12,940)	(12,661)	(13,256)	(13,277)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax	7	(158)	(19)	(14)
Amortization - Pension and postretirement benefits	511	709	853	1,181
Total other comprehensive income adjustments	518	551	834	1,167
Accumulated other comprehensive loss, end of period	$ (12,422)	$ (12,110)	$ (12,422)	$ (12,110)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of accumulated increase (decrease) in equity from transactions and other events and circumstances from non-owner sources, before Federal Home Loan Bank (FHLBank) assessments. Excludes net income (loss), and accumulated changes in equity from transactions resulting from investments by owners (distributions to owners). Includes, but is not limited to, foreign currency translation, certain pension adjustments, unrealized gain (loss) on certain investments in debt and equity securities, other than temporary impairment (OTTI) loss related to factors other than credit loss on available-for-sale and held-to-maturity debt securities, and increase (decrease) in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References

No definition available.

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- Definition

Amount before tax of other comprehensive income (loss) attributable to parent entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=84161450&loc=SL4573702-111684

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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=96868048&loc=SL4569616-111683

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- Definition

Amount, before tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580

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- Definition

Amount before tax and reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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