Other Postretirement Benefits (Components of Net Periodic Postretirement Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0us-gaap_DefinedBenefitPlanServiceCost	$ 0us-gaap_DefinedBenefitPlanServiceCost	$ 0us-gaap_DefinedBenefitPlanServiceCost
Interest cost	88us-gaap_DefinedBenefitPlanInterestCost	80us-gaap_DefinedBenefitPlanInterestCost	110us-gaap_DefinedBenefitPlanInterestCost
Amortization of unrecognized prior service cost	15	14	14
Net periodic pension cost	103	94	124
Discount rate	3.74%	4.45%	3.50%
Ultimate healthcare trend rates	4.00%
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	16	16	15
Interest cost	255	203	224
Amortization of unrecognized prior service cost	44	0	(1)
Loss amortization (2)	78	123	111
Net periodic pension cost	$ 393	$ 342	$ 349
Discount rate	3.70%	4.50%	3.50%
Annual rate of increase in the per capita cost of: Medical costs before age 65	8.00%	8.50%	9.00%
Annual rate of increase in the per capita cost of: Medical costs after age 65	7.00%	7.30%	7.50%
Annual rate of increase in the per capita cost of: Prescription drug costs	9.00%	7.80%	8.00%

Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year, Medical Costs After Age 65

No definition available.

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- Definition

Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year, Medical Costs Before Age 65

+ References

No definition available.

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- Definition

Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year, Prescription Drug Costs

+ References

No definition available.

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- Definition

The amount of gains or losses recognized in net periodic benefit cost.

+ References

+ Details

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- Definition

The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation.

+ References

+ Details

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- Definition

The interest rate used to adjust for the time value of money for the plan.

+ References

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- Definition

The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

+ References

+ Details

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- Definition

The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments.

+ References

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- Definition

The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the 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=35743120&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Service Cost (Component of Net Periodic Pension Cost)

-URI http://asc.fasb.org/extlink&oid=6525008

Reference 3: 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=35743120&loc=d3e1928-114920

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- Definition

The ultimate trend rate for health care costs.

+ References

+ Details

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