Postretirement Benefits (Details 3)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Weighted average discount rates:
Used to determine benefit obligations at December 31	4.25%	4.75%	4.00%
Used to determine net periodic postretirement benefit cost for years ended December 31	4.75%	4.00%	4.25%
Assumed health care cost trend rates at December 31:
Health care cost trend rate assumed for next year	7.00%	7.50%	8.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.00%	5.00%	5.00%
Year that rate reaches ultimate trend rate	2019	2019	2019

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The weighted average discount rates used to determine benefit obligations.

+ References

No definition available.

+ Details

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- Definition

The weighted average discount rates used to determine net periodic postretirement benefit cost.

+ References

No definition available.

+ Details

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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

+ Details

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- Definition

The ultimate trend rate for health care costs.

+ References

+ Details

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- Definition

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

+ References

+ Details

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