XML 128 R106.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Retirement Plans - Schedule of Target Allocation and Expected Long-Term Rate of Return by Asset Category (Detail) | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |
Target Allocation | 100.00% | 100.00%
Equity Securities in Financial Institutions [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target Allocation | 48.00% | 47.50%
Equity Securities in Financial Institutions [Member] | Minimum [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target Allocation | 20.00% |
Equity Securities in Financial Institutions [Member] | Maximum [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target Allocation | 50.00% |
Total Debt Securities [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target Allocation | 51.90% | 52.10%
Total Debt Securities [Member] | Minimum [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target Allocation | 30.00% |
Total Debt Securities [Member] | Maximum [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target Allocation | 60.00% |
Money Market Funds [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target Allocation | 0.10% | 0.40%
Money Market Funds [Member] | Minimum [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target Allocation | 20.00% |
Money Market Funds [Member] | Maximum [Member] |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Target Allocation | 30.00% |

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |