Retirement Benefit Plans (Details)	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%	100.00%
Fixed Income Funds [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	62.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	61.00%	61.00%
Equity Funds [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	38.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	38.00%	38.00%
Defined Benefit Plan, Cash and Cash Equivalents [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	1.00%	1.00%

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.

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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/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Percentage of actual 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/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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