Retirement Plans (Impact of One Percentage Point Change in Assumed Health Care and Dental Cost Trend Rates) (Details) (Postretirement Plan [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014
Postretirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Effect of one percentage point increase on service and interest cost components	$ 13
Effect of one percentage point decrease on service and interest cost components	(12)
Effect of one percentage point increase on postretirement benefit obligation	327
Effect of one percentage point decrease on postretirement benefit obligation	$ (289)

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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (m)

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

+ Details

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- Definition

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.

+ References

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- Definition

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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- Definition

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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