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Employee Benefits Allocation of Plan Assets (Details) | Dec. 31, 2018 | Dec. 31, 2017
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Allocation of Plan Assets |  |
Defined benefit plan, plan assets, target allocation, percentage | 100.00% |
Defined benefit plan, actual plan asset allocations | 100.00% | 100.00%
Alternative Investments |  |
Allocation of Plan Assets |  |
Defined benefit plan, plan assets, target allocation, percentage | 26.00% |
Defined benefit plan, actual plan asset allocations | 26.00% | 27.00%
Equity securities |  |
Allocation of Plan Assets |  |
Defined benefit plan, plan assets, target allocation, percentage | 23.00% |
Defined benefit plan, actual plan asset allocations | 22.00% | 23.00%
Fixed income securities |  |
Allocation of Plan Assets |  |
Defined benefit plan, plan assets, target allocation, percentage | 21.00% |
Defined benefit plan, actual plan asset allocations | 21.00% | 21.00%
Liability driven investments |  |
Allocation of Plan Assets |  |
Defined benefit plan, plan assets, target allocation, percentage | 16.00% |
Defined benefit plan, actual plan asset allocations | 16.00% | 14.00%
Real estate |  |
Allocation of Plan Assets |  |
Defined benefit plan, plan assets, target allocation, percentage | 6.00% |
Defined benefit plan, actual plan asset allocations | 6.00% | 6.00%
Other plan assets |  |
Allocation of Plan Assets |  |
Defined benefit plan, plan assets, target allocation, percentage | 8.00% |
Defined benefit plan, actual plan asset allocations | 9.00% | 9.00%

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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=112275985&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=108410482&loc=d3e1928-114920 + Details
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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=108410482&loc=d3e1928-114920 + Details
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