XML 94 R65.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Investments - Maturities of Fixed Maturities (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2021 | Dec. 31, 2020
Amortized Cost, net |  |
Due in 1 year or less | $ 245.4 |
Due after 1 year through 5 years | 1,613.8 |
Due after 5 years through 10 years | 1,600.5 |
Due after 10 years through 20 years | 1,339.9 |
Due after 20 years | 998.1 |
Amortized Cost, net | 5,797.7 | $ 5,788.6
Fair Value |  |
Due in 1 year or less | 250.8 |
Due after 1 year through 5 years | 1,686.2 |
Due after 5 years through 10 years | 1,729.5 |
Due after 10 years through 20 years | 1,488.2 |
Due after 20 years | 1,084.6 |
Total | $ 6,239.3 | $ 6,345.3
Percent of Total Fair Value |  |
Due in 1 year or less | 4.00% |
Due after 1 year through 5 years | 27.00% |
Due after 5 years through 10 years | 27.70% |
Due after 10 years through 20 years | 23.90% |
Due after 20 years | 17.40% |
Total | 100.00% |
Average option-adjusted duration, in years | 6 years 8 months 12 days |

X
- Definition Available for sale securities debt maturities a percentage of fair value. + References No definition available. + Details
Name: | hmn_AvailableForSaleSecuritiesDebtMaturitiesPercentageOfFairValue
Namespace Prefix: | hmn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Investment debt securities average option adjusted duration expressed in number of years. + References No definition available. + Details
Name: | hmn_AverageOptionAdjustedDurationInYears
Namespace Prefix: | hmn_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the eleventh rolling twelve months through the twentieth rolling twelve months following the latest balance sheet presented. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments. + References No definition available. + Details
Name: | hmn_DueAfter10YearsThrough20YearsAmortizedCost
Namespace Prefix: | hmn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of available-for-sale debt securities at fair value maturing in the eleventh rolling twelve months through the twentieth rolling twelve months following the latest balance sheet presented. + References No definition available. + Details
Name: | hmn_DueAfter10YearsThrough20YearsFairValue
Namespace Prefix: | hmn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Percentage of fair value of available for sale debt securities maturing in the eleventh rolling twelve months through the twentieth rolling twelve months following the latest balance sheet presented. + References No definition available. + Details
Name: | hmn_DueAfter10YearsThrough20YearsPercentOfTotalFairValue
Namespace Prefix: | hmn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of fair value of available for sale debt securities maturing in the second rolling twelve months through the fifth rolling twelve months following the latest balance sheet presented. + References No definition available. + Details
Name: | hmn_DueAfter1YearThrough5YearsPercentOfTotalFairValue
Namespace Prefix: | hmn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of available-for-sale debt securities at cost, net of adjustments, maturing after the twentieth rolling twelve months following the latest balance sheet presented. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, defined) and fair value hedge accounting adjustments. + References No definition available. + Details
Name: | hmn_DueAfter20YearsAmortizedCost
Namespace Prefix: | hmn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of available-for-sale debt securities at fair value maturing after the twentieth rolling twelve months following the latest balance sheet presented. + References No definition available. + Details
Name: | hmn_DueAfter20YearsFairValue
Namespace Prefix: | hmn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Percentage of fair value of available for sale debt securities maturing after the twentieth rolling twelve months following the latest balance sheet presented. + References No definition available. + Details
Name: | hmn_DueAfter20YearsPercentOfTotalFairValue
Namespace Prefix: | hmn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of fair value of available for sale debt securities maturing in the sixth rolling twelve months through the tenth rolling twelve months following the latest balance sheet presented. + References No definition available. + Details
Name: | hmn_DueAfter5YearsThrough10YearsPercentOfTotalFairValue
Namespace Prefix: | hmn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of fair value of available for sale debt securities maturing during the next rolling twelve months following the latest balance sheet presented. + References No definition available. + Details
Name: | hmn_DueIn1YearOrLessPercentOfTotalFairValue
Namespace Prefix: | hmn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of Total Fair Value [Abstract] + References No definition available. + Details
Name: | hmn_PercentageofTotalFairValueAbstract
Namespace Prefix: | hmn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amortized cost 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 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563 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 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in rolling sixth through tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in rolling sixth through tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year through fifth year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year through fifth year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasisRollingMaturityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateRollingMaturityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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