XML 51 R40.htm IDEA: XBRL DOCUMENT
v3.24.2.u1

Employee Benefit Plans - Narrative (Details) $ in Thousands | 1 Months Ended | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | --- | ---
Jan. 31, 2023 USD ($) | Jun. 30, 2024 USD ($) | Jun. 30, 2023 USD ($) | Jun. 30, 2024 USD ($) | Jun. 30, 2023 USD ($) | Sep. 30, 2024 USD ($) | Dec. 31, 2020 plan
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Number of defined benefit plans (in plans) | plan |  |  |  |  |  |  | 2
Pension plan termination charges |  | $ 38,217 | $ 0 | $ 38,217 | $ 0 |  |
Nonqualified Plan |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Benefit payments |  |  |  | 900 | $ 900 |  |
Qualified Plan I | Qualified Plan |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Termination term (in months) | 18 months |  |  |  |  |  |
Cash contribution to terminate | $ 7,400 |  |  |  |  |  |
Cash contribution, termination amount |  | 6,100 |  |  |  |  |
Qualified Plan I | Qualified Plan | Forecast |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Amount expected to be paid |  |  |  |  |  | $ 1,300 |
Qualified Plan II |  |  |  |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |  |  |  |
Contribution |  | $ 2,000 |  | 2,000 |  |  |
Benefit payments |  |  |  | $ 800 |  |  |

X
- Definition Defined Benefit Plan, Cash Contribution, Termination Amount + References No definition available. + Details
Name: | hrth_DefinedBenefitPlanCashContributionTerminationAmount
Namespace Prefix: | hrth_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Defined Benefit Plan, Expected Future Benefit Payment + References No definition available. + Details
Name: | hrth_DefinedBenefitPlanExpectedFutureBenefitPayment
Namespace Prefix: | hrth_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Defined Benefit Plan, Number Of Plans + References No definition available. + Details
Name: | hrth_DefinedBenefitPlanNumberOfPlans
Namespace Prefix: | hrth_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Termination Costs + References No definition available. + Details
Name: | hrth_DefinedBenefitPlanTerminationCosts
Namespace Prefix: | hrth_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Defined Benefit Plan, Termination Term + References No definition available. + Details
Name: | hrth_DefinedBenefitPlanTerminationTerm
Namespace Prefix: | hrth_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of contribution received by defined benefit plan from employer which increases plan assets. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480482/715-20-55-17 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 18 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480482/715-20-55-18 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix: | us-gaap_
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 No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_RetirementPlanTaxStatusAxis=us-gaap_NonqualifiedPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=hrth_QualifiedPlanIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTaxStatusAxis=us-gaap_QualifiedPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=hrth_QualifiedPlanIIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |