XML 40 R29.htm IDEA: XBRL DOCUMENT
v3.21.1

Basis of Presentation (Details) - USD ($) $ in Millions |  | 3 Months Ended
--- | --- | ---
Apr. 01, 2021 | Mar. 31, 2021 | Mar. 31, 2020
Stock-based Compensation Awards [Member] |  |  |
Basis of Presentation [Abstract] |  |  |
Antidilutive securities excluded from diluted EPS calculation (in shares) |  | 0 |
Diamond Offshore [Member] |  |  |
Basis of Presentation [Abstract] |  |  |
Asset impairment charge |  |  | $ 774
Asset impairment charge, after tax and noncontrolling interests |  |  | $ 408
CNA [Member] |  |  |
Basis of Presentation [Abstract] |  |  |
Subsidiary ownership percentage |  | 89.50% |
Altium Packaging LLC [Member] |  |  |
Basis of Presentation [Abstract] |  |  |
Subsidiary ownership percentage |  | 99.00% |
Subsequent Event [Member] | Altium Packaging LLC [Member] |  |  |
Basis of Presentation [Abstract] |  |  |
Percentage interest of subsidiary sold | 47.00% |  |

X
- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill, net of tax and noncontrolling interest. + References No definition available. + Details
Name: | l_AssetImpairmentChargesNetOfTaxAndNoncontrollingInterest
Namespace Prefix: | l_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition The ownership interest in the subsidiary sold. + References No definition available. + Details
Name: | l_DisposalGroupSubsidiarySoldPercentage
Namespace Prefix: | l_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228 + Details
Name: | us-gaap_AssetImpairmentCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=us-gaap_StockCompensationPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=l_DiamondOffshoreDrillingIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=l_CnaFinancialCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=l_AltiumPackagingLlcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |