Name:	hmn_AssumedInsurancePremiumsAndContractChargesEarned
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Data Type:	xbrli:monetaryItemType
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Insurance premiums written and contract deposits for all insurance contracts assumed from other insurers as a result of reinsurance arrangements.

No definition available.

Name:	hmn_AssumedInsurancePremiumsWrittenAndContractDeposits
Namespace Prefix:	hmn_
Data Type:	xbrli:monetaryItemType
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Insurance premiums and contract charges assumed and earned by another insurer as a result of reinsurance arrangements.

No definition available.

Name:	hmn_CededInsurancePremiumsAndContractChargesEarned
Namespace Prefix:	hmn_
Data Type:	xbrli:monetaryItemType
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Insurance premiums written and contract deposits assumed by another insurer as a result of reinsurance arrangements.

No definition available.

Name:	hmn_CededInsurancePremiumsWrittenAndContractDeposits
Namespace Prefix:	hmn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The sum of insurance premiums earned, premiums earned on the income statement for all insurance contracts before subtracting any amounts ceded to another insurer or adding premiums assumed from other insurers, plus contract charges earned on investment and universal life-type contracts.

No definition available.

Name:	hmn_DirectInsurancePremiumsAndContractChargesEarned
Namespace Prefix:	hmn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The sum of insurance premiums written for all insurance contracts before subtracting any amounts ceded to another insurer or adding premiums assumed from other insurers plus contract deposits on investment and universal life-type contracts.

No definition available.

Name:	hmn_DirectInsurancePremiumsWrittenAndContractDeposits
Namespace Prefix:	hmn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The sum of insurance premiums earned, premiums earned on the income statement for all insurance contracts after subtracting any amounts ceded to another insurer and adding premiums assumed from other insurers, plus contract charges earned on investment and universal life-type contracts.

No definition available.

Name:	hmn_InsurancePremiumsAndContractChargesEarned
Namespace Prefix:	hmn_
Data Type:	xbrli:monetaryItemType
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The sum of insurance premiums written for all insurance contracts after subtracting any amounts ceded to another insurer and adding premiums assumed from other insurers, plus contract deposits on investment and universal life-type contracts.

No definition available.

Name:	hmn_InsurancePremiumsWrittenAndContractDeposits
Namespace Prefix:	hmn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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Amount, before effect of policies assumed or ceded, of expense related to provision for policy benefits and costs incurred.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.5)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 5

-Article 7

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 20

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6811-158387

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_ReinsuranceDisclosuresAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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Amount of policy benefits and costs incurred for policies assumed.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 20

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6811-158387

Name:	us-gaap_ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountAssumed
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Amount of reduction of provision for policy benefits and costs incurred for policies ceded.