XML 116 R101.htm IDEA: XBRL DOCUMENT
v3.20.4

Employee Benefit Plans (Pension Plan's Weighted-average Asset Allocations) (Details) | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Defined Benefit Plan, Information about Plan Assets [Abstract] |  |
Weighted average asset allocations | 100.00% | 100.00%
U.S. Equity [Member] |  |
Defined Benefit Plan, Information about Plan Assets [Abstract] |  |
Weighted average asset allocations | 34.80% | 44.60%
International Equity [Member] |  |
Defined Benefit Plan, Information about Plan Assets [Abstract] |  |
Weighted average asset allocations | 17.00% | 7.30%
Fixed Income [Member] |  |
Defined Benefit Plan, Information about Plan Assets [Abstract] |  |
Weighted average asset allocations | 48.00% | 48.00%
Money Market |  |
Defined Benefit Plan, Information about Plan Assets [Abstract] |  |
Weighted average asset allocations | 0.20% | 0.10%

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

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

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

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