Pension and Other Postretirement Benefits (Details 10) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014
Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in next fiscal year	$ 5,169
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2015	29,161
2016	29,319
2017	29,471
2018	29,745
2019	30,570
Years 2020-2024	151,904
Total	300,170
Other postretirement benefit plans [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2015	4,547
2016	4,177
2017	3,971
2018	4,108
2019	3,846
Years 2020-2024	16,112
Total	$ 36,761

Defined Benefit Plan, Expected Future Benefit Payments

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- Definition

Amount of benefits expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year from a defined benefit 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 (f)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

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- Definition

Amount of benefits expected to be paid in the next fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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- Definition

Amount of benefits expected to be paid in the fourth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the third fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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- Definition

Amount of benefits expected to be paid in the second fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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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=28361610&loc=d3e1928-114920

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