XML 82 R69.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Employee Benefits - Plan Assets and Investment Policy (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Employee Benefits |  |
Weighted-average asset allocations (as a percent) | 100.00% | 100.00%
Fair value of plan assets | $ 94.9 | $ 89.0
Level 1 |  |
Employee Benefits |  |
Fair value of plan assets | 63.3 | 63.4
Level 2 |  |
Employee Benefits |  |
Fair value of plan assets | 31.6 | 25.6
Equity securities |  |
Employee Benefits |  |
Fair value of plan assets | 27.5 | 26.7
Equity securities | Level 1 |  |
Employee Benefits |  |
Fair value of plan assets | 27.5 | 26.7
U.S. government, state, and agency |  |
Employee Benefits |  |
Fair value of plan assets | 11.6 | 4.7
U.S. government, state, and agency | Level 2 |  |
Employee Benefits |  |
Fair value of plan assets | 11.6 | 4.7
Corporate debt securities |  |
Employee Benefits |  |
Fair value of plan assets | 17.4 | 17.4
Corporate debt securities | Level 2 |  |
Employee Benefits |  |
Fair value of plan assets | 17.4 | 17.4
Mutual funds |  |
Employee Benefits |  |
Fair value of plan assets | 34.8 | 34.3
Mutual funds | Level 1 |  |
Employee Benefits |  |
Fair value of plan assets | 32.2 | 30.8
Mutual funds | Level 2 |  |
Employee Benefits |  |
Fair value of plan assets | 2.6 | 3.5
Interest and non-interest bearing cash |  |
Employee Benefits |  |
Fair value of plan assets | 3.6 | 5.9
Interest and non-interest bearing cash | Level 1 |  |
Employee Benefits |  |
Fair value of plan assets | $ 3.6 | $ 5.9
Equity securities |  |
Employee Benefits |  |
Weighted-average asset allocations (as a percent) | 51.00% | 55.00%
Equity securities | Minimum |  |
Target allocation |  |
Target allocation (as a percent) | 35.00% |
Equity securities | Maximum |  |
Target allocation |  |
Target allocation (as a percent) | 65.00% |
Debt securities |  |
Employee Benefits |  |
Weighted-average asset allocations (as a percent) | 45.00% | 38.00%
Debt securities | Minimum |  |
Target allocation |  |
Target allocation (as a percent) | 15.00% |
Debt securities | Maximum |  |
Target allocation |  |
Target allocation (as a percent) | 45.00% |
Other |  |
Employee Benefits |  |
Weighted-average asset allocations (as a percent) | 4.00% | 7.00%
Other | Minimum |  |
Target allocation |  |
Target allocation (as a percent) | 0.00% |
Other | Maximum |  |
Target allocation |  |
Target allocation (as a percent) | 15.00% |

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

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 Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees. + 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 (b) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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

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

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=rs_OtherSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |