XML 59 R41.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Fair Value of Financial Instruments - Narrative (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016
Fair Value of Financial Instruments (Textual) [Abstract] |  |  |  |
Realized loss on impairment of securities |  |  | $ 1,714 |
Level 3 |  |  |  |
Fair Value of Financial Instruments (Textual) [Abstract] |  |  |  |
Percentage of invested assets in total investment portfolio Level 3 recurring | 3.10% |  | 3.10% |
Net realized investment losses | $ 1,238 | $ 1,324 | $ 3,546 | $ 1,998

X
- Definition Fair value of financial instruments. + References No definition available. + Details
Name: | hmn_FairValueOfFinancialInstrumentsTextualAbstract
Namespace Prefix: | hmn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of invested assets in the total investment portfolio in Level 3 carried at fair value on a recurring basis. + References No definition available. + Details
Name: | hmn_PercentageOfInvestedAssetsInTotalInvestmentPortfolioLevel3Recurring
Namespace Prefix: | hmn_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of loss realized on the sale of debt or equity securities classified as available-for-sale. Excludes other than temporary impairments (OTTI). + References No definition available. + Details
Name: | us-gaap_AvailableforsaleSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959 + Details
Name: | us-gaap_EmbeddedDerivativeGainLossOnEmbeddedDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |