XML 66 R50.htm IDEA: XBRL DOCUMENT
v3.24.3

Short- Duration Insurance Contracts - Narrative (Details) - USD ($) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023
Property & Casualty |  |  |  |
Net Amount at Risk by Product and Guarantee [Line Items] |  |  |  |
Decrease in estimated reserves for claims occurring in prior years | $ (13,000,000.0) | $ 0 | $ (19,200,000) | $ 0
Favorable (unfavorable) development of total reserves for claims occurring in prior years | 13,000,000 | 0 | 19,200,000 | 0
Group Benefits |  |  |  |
Net Amount at Risk by Product and Guarantee [Line Items] |  |  |  |
Decrease in estimated reserves for claims occurring in prior years | $ (3,900,000) | $ (7,600,000) | (13,200,000) | (15,500,000)
Favorable (unfavorable) development of total reserves for claims occurring in prior years |  |  | $ 13,200,000 | $ 15,500,000

X
- Definition Favorable (Unfavorable) Development Of Total Reserves For Claims Occurring In Prior Years + References No definition available. + Details
Name: | hmn_FavorableUnfavorableDevelopmentOfTotalReservesForClaimsOccurringInPriorYears
Namespace Prefix: | hmn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 15 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479808/944-20-55-15 + Details
Name: | us-gaap_NetAmountAtRiskByProductAndGuaranteeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after effects of reinsurance, of expense (reversal of expense) for claims incurred in prior reporting periods and related claims settlement costs. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-3 + Details
Name: | us-gaap_SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | srt_ProductOrServiceAxis=hmn_ProductAndCasualtySegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=hmn_GroupBenefitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |