XML 41 R30.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Basis of Presentation - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Dec. 31, 2015 | Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015
Employee Stock Option [Member] |  |  |  |  |
Subsidiary or Equity Method Investee [Line Items] |  |  |  |  |
Shares excluded from diluted EPS calculation |  | 3.3 | 5.8 | 4.7 | 4.5
Accounting Standards Update 2015-03 [Member] |  |  |  |  |
Subsidiary or Equity Method Investee [Line Items] |  |  |  |  |
Decrease in other assets and long term debt | $ 23 |  |  |  |
CNA Financial [Member] |  |  |  |  |
Subsidiary or Equity Method Investee [Line Items] |  |  |  |  |
Subsidiary ownership percentage |  |  |  | 90.00% |
Diamond Offshore Drilling, Inc. [Member] |  |  |  |  |
Subsidiary or Equity Method Investee [Line Items] |  |  |  |  |
Subsidiary ownership percentage |  |  |  | 53.00% |
Boardwalk Pipeline Partners, LP [Member] |  |  |  |  |
Subsidiary or Equity Method Investee [Line Items] |  |  |  |  |
Subsidiary ownership percentage |  |  |  | 51.00% |

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/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Antidilution -URI http://asc.fasb.org/extlink&oid=6505113 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Diluted Earnings Per Share -URI http://asc.fasb.org/extlink&oid=6510752 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Contingent Stock Agreement -URI http://asc.fasb.org/extlink&oid=6508534 Reference 4: http://www.xbrl.org/2003/role/presentationRef -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 Represents the quantification of the effect of adopting the new accounting standard or change in accounting principle expected by the entity to have a significant effect on the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions. + References No definition available. + Details
Name: | us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
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_SubsidiaryOrEquityMethodInvesteeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201503Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | dei_LegalEntityAxis=l_BoardwalkPipelinePartnersLpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |