Pension Plans and Other Postretirement Benefits (Details-3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Benefits [Member]
Weighted-average assumptions used to determine benefit obligations:
Discount rate	4.11%	4.88%
Rate of compensation increase	3.85%	3.90%
Weighted-average assumptions used to determine net periodic cost:
Discount rate	4.88%	4.09%	4.50%
Long-term rate of return	8.10%	8.10%	8.10%
Rate of compensation increase	3.93%	4.60%	4.59%
Postretirement Benefits [Member]
Weighted-average assumptions used to determine benefit obligations:
Discount rate	3.96%	4.69%
Assumed health care cost trend rates:
Health care cost trend rate assumed for next year	6.50%	7.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.00%	5.00%
Year that the rate reaches the ultimate trend rate	2021	2018
Weighted-average assumptions used to determine net periodic cost:
Discount rate	4.69%	4.14%	4.55%
Long-term rate of return	7.07%	6.79%	7.26%
How assumed 1% increase or decrease in health care cost trends could impact postretirement benefits [Abstract]
Effect on other postretirement benefit obligation - 1% increase	1,465
Effect on other postretirement benefit obligation - 1% decrease	(1,852)
Effect on total service and interest cost components - 1% increase	75
Effect on total service and interest cost components - 1% decrease	(101)

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

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Expected rate of compensation increases (for pay-related plans).

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

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- Definition

An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Glossary Expected Long-Term Rate of Return on Plan Assets

-URI http://asc.fasb.org/extlink&oid=6512013

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (k)(3)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

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Expected rate of compensation increases (for pay-related plans).

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Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

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Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

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The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

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The effect of a one-percentage-point increase in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

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- Definition

The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status.

+ 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 (l)

-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 Health Care Cost Trend Rate

-URI http://asc.fasb.org/extlink&oid=6514820

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The ultimate trend rate for health care costs.

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Year the ultimate health care cost trend rate is expected to be reached, in CCYY format.

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