Pension and Other Postretirement Benefits Expected Contribution Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014
Defined Benefit Pension Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$ 5,306
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	17,487
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	17,965
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	18,191
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	19,958
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	19,830
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	97,247
Other Postretirement Benefit Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	6,118
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	6,118
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	6,605
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	7,212
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	7,691
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	8,216
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	$ 43,357

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Amount of benefits from a defined benefit plan expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ 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 (f)

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

+ Details

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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- Definition

Amount of benefits from a defined benefit plan expected to be paid in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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- Definition

Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position.

+ 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 (g)

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

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