Employee Retirement Plans (Details 5)	12 Months Ended
Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations	100.00%
Equity
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations	39.00%
Target plan asset allocations, range minimum	35.00%
Target plan asset allocations, range maximum	43.00%
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations	49.00%
Target plan asset allocations, range minimum	38.00%
Target plan asset allocations, range maximum	61.00%
Limited partnerships
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations	6.00%
Target plan asset allocations, range minimum	2.00%
Target plan asset allocations, range maximum	8.00%
Other real assets
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations	6.00%
Target plan asset allocations, range minimum	3.00%
Target plan asset allocations, range maximum	10.00%
Cash equivalents and short-term investments
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations	0.00%
Target plan asset allocations, range minimum	0.00%
Target plan asset allocations, range maximum	5.00%

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Target allocation of investments of this type to total plan assets presented on a weighted average basis.

+ 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 (d)(i)

-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

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (c)(i)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2446-114920

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