XML 42 R32.htm IDEA: XBRL DOCUMENT
v3.22.2

Investments - Assets Measured at Fair Value (Details) - USD ($) $ in Thousands | Jun. 30, 2022 | Dec. 31, 2021
--- | --- | ---
Assets measured at Fair Value |  |
Available-for-sale fixed income | $ 2,280,909 | $ 2,409,887
Equity securities | 487,995 | 613,776
Municipal |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 558,795 | 645,756
Fair Value Measured on Recurring Basis |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 2,280,909 | 2,409,887
Equity securities | 487,995 | 613,776
Total assets at fair value | 2,768,904 | 3,023,663
Fair Value Measured on Recurring Basis | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |
Assets measured at Fair Value |  |
Equity securities | 486,780 | 613,712
Total assets at fair value | 486,780 | 613,712
Fair Value Measured on Recurring Basis | Significant Other Observable Inputs (Level 2) |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 2,225,294 | 2,366,369
Equity securities | 42 | 64
Total assets at fair value | 2,225,336 | 2,366,433
Fair Value Measured on Recurring Basis | Significant Unobservable Inputs (Level 3) |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 55,615 | 43,518
Equity securities | 1,173 |
Total assets at fair value | 56,788 | 43,518
Fair Value Measured on Recurring Basis | U.S. government |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 181,678 | 134,554
Fair Value Measured on Recurring Basis | U.S. government | Significant Other Observable Inputs (Level 2) |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 181,678 | 134,554
Fair Value Measured on Recurring Basis | U.S. Agency |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 33,573 | 32,760
Fair Value Measured on Recurring Basis | U.S. Agency | Significant Other Observable Inputs (Level 2) |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 33,573 | 32,760
Fair Value Measured on Recurring Basis | Non-U.S. government & agency |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 6,068 | 8,481
Fair Value Measured on Recurring Basis | Non-U.S. government & agency | Significant Other Observable Inputs (Level 2) |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 6,068 | 8,481
Fair Value Measured on Recurring Basis | Agency MBS |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 312,721 | 367,187
Fair Value Measured on Recurring Basis | Agency MBS | Significant Other Observable Inputs (Level 2) |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 312,721 | 367,187
Fair Value Measured on Recurring Basis | ABS/CMBS/MBS |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 246,345 | 264,054
Fair Value Measured on Recurring Basis | ABS/CMBS/MBS | Significant Other Observable Inputs (Level 2) |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 246,345 | 264,054
Fair Value Measured on Recurring Basis | Corporate Debt |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 941,729 | 957,095
Fair Value Measured on Recurring Basis | Corporate Debt | Significant Other Observable Inputs (Level 2) |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 886,114 | 913,577
Fair Value Measured on Recurring Basis | Corporate Debt | Significant Unobservable Inputs (Level 3) |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 55,615 | 43,518
Fair Value Measured on Recurring Basis | Municipal |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | 558,795 | 645,756
Fair Value Measured on Recurring Basis | Municipal | Significant Other Observable Inputs (Level 2) |  |
Assets measured at Fair Value |  |
Available-for-sale fixed income | $ 558,795 | $ 645,756

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=123594786&loc=SL75136599-209740 + Details
Name: | us-gaap_EquitySecuritiesFvNi
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=rli_AssetBackedSecuritiesAndCommercialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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