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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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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 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
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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

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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
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-Section 50
-Paragraph 5
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-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)
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-Name Accounting Standards Codification
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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Pension and Other Postretirement Benefits - Pension Plan Assets Allocation (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity securities
Target investment allocation and permissible allocation range for plan assets
Strategic Target (as a percent)	43.00%
Debt securities
Target investment allocation and permissible allocation range for plan assets
Strategic Target (as a percent)	57.00%
Pension Benefits
Pension plan
Percentage of Plan Assets	100.00%	100.00%	100.00%
Pension Benefits \| Equity securities
Pension plan
Percentage of Plan Assets	43.00%	34.00%	35.00%
Target investment allocation and permissible allocation range for plan assets
Strategic Target (as a percent)	43.00%
Permitted Range, minimum (as a percent)	38.00%
Permitted Range, maximum (as a percent)	48.00%
Pension Benefits \| Debt securities
Pension plan
Percentage of Plan Assets	57.00%	64.00%	65.00%
Target investment allocation and permissible allocation range for plan assets
Strategic Target (as a percent)	57.00%
Permitted Range, minimum (as a percent)	52.00%
Permitted Range, maximum (as a percent)	62.00%
Pension Benefits \| Cash and money-market funds
Pension plan
Percentage of Plan Assets	0.00%	2.00%	0.00%