Pension and Other Post-Retirement Benefit Plans (Plan Asset Allocations) (Details)	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation	100.00%	100.00%
Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation	1.00%	1.00%
Asset allocation range, minimum	0.00%
Asset allocation range, maximum	5.00%
Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation	30.00%	28.00%
Asset allocation range, minimum	15.00%
Asset allocation range, maximum	35.00%
Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation	64.00%	67.00%
Asset allocation range, minimum	60.00%
Asset allocation range, maximum	80.00%
Real estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation	5.00%	4.00%
Asset allocation range, minimum	0.00%
Asset allocation range, maximum	5.00%
US Treasury Securities [Member] \| Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation range, maximum	5.00%
US Treasury Securities [Member] \| Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocation range, maximum	10.00%

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No definition available.

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Target allocation maximum percentage 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 5
-Subparagraph (c)(i)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e2446-114920

Reference 2: 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=65897934&loc=d3e1928-114920

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Target allocation minimum percentage 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=65897934&loc=d3e1928-114920

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)(i)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e2446-114920

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Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e2446-114920

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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