XML 113 R64.htm IDEA: XBRL DOCUMENT v2.4.1.9
Fair Value of Financial Instruments (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
U.S. government and federally sponsored agency obligations    
Investments, Carrying Value $ 7,403,467us-gaap_Investments $ 6,539,473us-gaap_Investments
Investments, Fair Value 149,792us-gaap_InvestmentsFairValueDisclosure 144,921us-gaap_InvestmentsFairValueDisclosure
Separate Account (variable annuity) assets, Carrying Value 1,813,557us-gaap_SeparateAccountAssets 1,747,995us-gaap_SeparateAccountAssets
Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Carrying Amount 6,893,090us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 6,009,573us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Fair Value 6,893,090hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 6,009,573hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Investments, Carrying Value 7,158,242us-gaap_Investments
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 6,313,189us-gaap_Investments
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Investments, Fair Value 7,158,242us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 6,313,189us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Separate Account (variable annuity) assets, Carrying Value 1,813,557us-gaap_SeparateAccountAssets
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 1,747,995us-gaap_SeparateAccountAssets
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Separate Account (variable annuity) assets, Fair Value 1,813,557hmn_SeparateAccountAssetsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 1,747,995hmn_SeparateAccountAssetsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Financial Liabilities Carrying Amount 20,049hmn_LiabilitiesCarryingAmount
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 0hmn_LiabilitiesCarryingAmount
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Financial Liabilities Fair value 20,049us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Short-term investments [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Investments, Carrying Value 142,039us-gaap_Investments
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 206,758us-gaap_Investments
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember
Investments, Fair Value 142,039us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 206,758us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember
Mortgage-backed securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 535,726hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		 569,725hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Mortgage-backed securities [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Carrying Amount 535,726us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		 569,725us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Other including U.S. Treasury Securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 538,199hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherIncludingUsTreasurySecuritiesMember		 435,574hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherIncludingUsTreasurySecuritiesMember
Other including U.S. Treasury Securities [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Carrying Amount 538,199us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherIncludingUsTreasurySecuritiesMember		 435,574us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherIncludingUsTreasurySecuritiesMember
Municipal Bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 1,647,822hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember		 1,471,527hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Municipal Bonds [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Carrying Amount 1,647,822us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember		 1,471,527us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Foreign government bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 59,536hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ForeignGovernmentDebtMember		 54,951hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ForeignGovernmentDebtMember
Foreign government bonds [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Carrying Amount 59,536us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ForeignGovernmentDebtMember		 54,951us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ForeignGovernmentDebtMember
Corporate Bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 2,834,749hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 2,614,409hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Corporate Bonds [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Carrying Amount 2,834,749us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 2,614,409us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Other Mortgage-backed Securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 1,277,058hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesOtherMember		 863,387hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesOtherMember
Other Mortgage-backed Securities [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Carrying Amount 1,277,058us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesOtherMember		 863,387us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesOtherMember
Equity Securities [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Carrying Amount 110,655us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember		 91,858us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
Fair Value 110,655hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember		 91,858hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
Other investments | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Investments, Carrying Value 12,458us-gaap_Investments
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherPolicyholdersFundsEmbeddedDerivativesMember		 5,000us-gaap_Investments
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherPolicyholdersFundsEmbeddedDerivativesMember
Investments, Fair Value 12,458us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherPolicyholdersFundsEmbeddedDerivativesMember		 5,000us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherPolicyholdersFundsEmbeddedDerivativesMember
Level 1 [Member]    
U.S. government and federally sponsored agency obligations    
Investments, Fair Value 0us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member		 0us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
Level 1 [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 28,381hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 27,938hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Investments, Fair Value 262,560us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 308,571us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Separate Account (variable annuity) assets, Fair Value 1,813,557hmn_SeparateAccountAssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 1,747,995hmn_SeparateAccountAssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Financial Liabilities Fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Level 1 [Member] | Short-term investments [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Investments, Fair Value 142,039us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 206,354us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember
Level 1 [Member] | Mortgage-backed securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 0hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		 0hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Level 1 [Member] | Other including U.S. Treasury Securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 17,857hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherIncludingUsTreasurySecuritiesMember		 17,757hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherIncludingUsTreasurySecuritiesMember
Level 1 [Member] | Municipal Bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 0hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember		 0hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Level 1 [Member] | Foreign government bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 0hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ForeignGovernmentDebtMember		 0hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ForeignGovernmentDebtMember
Level 1 [Member] | Corporate Bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 10,524hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 10,181hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Level 1 [Member] | Other Mortgage-backed Securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 0hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesOtherMember		 0hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesOtherMember
Level 1 [Member] | Equity Securities [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 92,140hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember		 74,279hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
Level 1 [Member] | Other investments | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Investments, Fair Value 0us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherPolicyholdersFundsEmbeddedDerivativesMember		 0us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hmn_OtherPolicyholdersFundsEmbeddedDerivativesMember
Level 2 [Member]    
U.S. government and federally sponsored agency obligations    
Investments, Fair Value 0us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member		 0us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Level 2 [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 6,693,415hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 5,872,106hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Investments, Fair Value 6,724,382us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 5,895,083us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Separate Account (variable annuity) assets, Fair Value 0hmn_SeparateAccountAssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 0hmn_SeparateAccountAssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Financial Liabilities Fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Level 2 [Member] | Short-term investments [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Investments, Fair Value 0us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 404us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember
Level 2 [Member] | Mortgage-backed securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 535,726hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember		 569,725hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 2 [Member] | Other including U.S. Treasury Securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 520,342hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 2 [Member] | Municipal Bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 1,634,194hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 2 [Member] | Foreign government bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 59,536hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 2 [Member] | Corporate Bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 2,749,508hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 2 [Member] | Other Mortgage-backed Securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 1,194,109hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesOtherMember		 817,378hmn_AvailableForSaleSecuritiesFairValue
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 2 [Member] | Equity Securities [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 18,509hmn_AvailableForSaleSecuritiesFairValue
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/ us-gaap_FairValueByMeasurementFrequencyAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 2 [Member] | Other investments | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Investments, Fair Value 12,458us-gaap_InvestmentsFairValueDisclosure
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 3 [Member]    
U.S. government and federally sponsored agency obligations    
Investments, Fair Value 149,792us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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Level 3 [Member] | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 171,294hmn_AvailableForSaleSecuritiesFairValue
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/ us-gaap_FairValueByMeasurementFrequencyAxis
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/ us-gaap_FairValueByMeasurementFrequencyAxis
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Investments, Fair Value 171,300us-gaap_InvestmentsFairValueDisclosure
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/ us-gaap_FairValueByMeasurementFrequencyAxis
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/ us-gaap_FairValueByMeasurementFrequencyAxis
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Financial Liabilities Fair value 20,049us-gaap_LiabilitiesFairValueDisclosure
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/ us-gaap_FairValueByMeasurementFrequencyAxis
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/ us-gaap_FairValueByMeasurementFrequencyAxis
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U.S. government and federally sponsored agency obligations    
Investments, Fair Value 0us-gaap_InvestmentsFairValueDisclosure
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/ us-gaap_FairValueByMeasurementFrequencyAxis
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/ us-gaap_FairValueByMeasurementFrequencyAxis
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/ us-gaap_InvestmentTypeAxis
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U.S. government and federally sponsored agency obligations    
Fair Value 0hmn_AvailableForSaleSecuritiesFairValue
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 3 [Member] | Other including U.S. Treasury Securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 0hmn_AvailableForSaleSecuritiesFairValue
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 3 [Member] | Municipal Bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 13,628hmn_AvailableForSaleSecuritiesFairValue
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 3 [Member] | Foreign government bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 0hmn_AvailableForSaleSecuritiesFairValue
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Level 3 [Member] | Corporate Bonds [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 74,717hmn_AvailableForSaleSecuritiesFairValue
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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Level 3 [Member] | Other Mortgage-backed Securities [Member]    
U.S. government and federally sponsored agency obligations    
Fair Value 82,949hmn_AvailableForSaleSecuritiesFairValue
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/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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U.S. government and federally sponsored agency obligations    
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Level 3 [Member] | Other investments | Recurring [Member]    
U.S. government and federally sponsored agency obligations    
Investments, Fair Value $ 0us-gaap_InvestmentsFairValueDisclosure
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[1] Separate Account (variable annuity) liabilities are set equal to Separate Account (variable annuity) assets.