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.

No definition available.

+ Details

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- Definition

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one 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 (d)(5)(i)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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- Definition

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=82843861&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)(1)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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- Details

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Employee Benefit Plans - Summary of plan weighted average asset allocation by asset category along with target allocation for 2018 (Details 6)	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	100.00%	100.00%
Cash and Cash Equivalents \| Retirement Income Plan
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	2.80%	3.30%
Cash and Cash Equivalents \| Retirement Income Plan \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation for 2018 minimum percentage	0.00%
Cash and Cash Equivalents \| Retirement Income Plan \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation for 2018 minimum percentage	3.00%
Fixed income securities \| Retirement Income Plan
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	23.80%	25.30%
Fixed income securities \| Retirement Income Plan \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation for 2018 minimum percentage	15.00%
Fixed income securities \| Retirement Income Plan \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation for 2018 minimum percentage	25.00%
Domestic Equity Securities \| Retirement Income Plan
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	42.40%	25.50%
Domestic Equity Securities \| Retirement Income Plan \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation for 2018 minimum percentage	0.00%
Domestic Equity Securities \| Retirement Income Plan \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation for 2018 minimum percentage	40.00%
International Equity Securities \| Retirement Income Plan
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	20.70%	20.80%
International Equity Securities \| Retirement Income Plan \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation for 2018 minimum percentage	0.00%
International Equity Securities \| Retirement Income Plan \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation for 2018 minimum percentage	20.00%
Investments measured at net asset value \| Retirement Income Plan
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	10.30%	25.10%
Investments measured at net asset value \| Retirement Income Plan \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation for 2018 minimum percentage	0.00%
Investments measured at net asset value \| Retirement Income Plan \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation for 2018 minimum percentage	12.00%