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Employee Benefit Plans - Weighted Average Asset Allocations by Asset Category (Detail) | Dec. 31, 2018 | Dec. 31, 2017
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Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items] |  |
Actual Asset Allocation as of December 31 | 100.00% | 100.00%
Target Asset | 100.00% |
Equity securities |  |
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items] |  |
Actual Asset Allocation as of December 31 | 32.00% | 32.00%
Target Asset | 32.00% |
Debt securities |  |
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items] |  |
Actual Asset Allocation as of December 31 | 51.00% | 41.00%
Target Asset | 50.00% |
Insurance (annuity) contracts |  |
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items] |  |
Actual Asset Allocation as of December 31 | 12.00% | 17.00%
Target Asset | 12.00% |
Real-estate |  |
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items] |  |
Actual Asset Allocation as of December 31 | 3.00% | 8.00%
Target Asset | 3.00% |
Other |  |
Schedule of Defined Benefit Plan Asset Allocation Targets [Line Items] |  |
Actual Asset Allocation as of December 31 | 2.00% | 2.00%
Target Asset | 3.00% |

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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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