XML 76 R52.htm IDEA: XBRL DOCUMENT
v3.21.2

Note 11 - Commitments, Contingencies and Obligations (Details Textual) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Jul. 31, 2018 | Dec. 31, 2014 | Aug. 31, 2012 | Jun. 30, 2011 | Sep. 30, 2021 | Mar. 31, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020
Environmental Remediation Expense |  |  |  |  | $ 7,564 |  | $ 1,254 | $ 12,297 | $ 2,807 |
Contractual Obligation, Total |  |  |  |  | 700 |  |  | 700 |  |
Finance Lease, Liability, Payment, Due, Total |  |  |  |  | 15,094 |  |  | 15,094 |  |
Lessee, Operating Lease, Liability, to be Paid, Total |  |  |  |  | 9,803 |  |  | 9,803 |  |
Performance Obligation Commitments [Member] |  |  |  |  |  |  |  |  |  |
Surety Bonds |  |  |  |  | 182,600 |  |  | 182,600 |  |
Letters of Credit Outstanding, Amount |  |  |  |  | 21,000 |  |  | 21,000 |  |
Lucky Friday [Member] |  |  |  |  |  |  |  |  |  |
Open Purchase Orders |  |  |  |  | 8,500 |  |  | 8,500 |  |
Casa Berardi [Member] |  |  |  |  |  |  |  |  |  |
Open Purchase Orders |  |  |  |  | 500 |  |  | 500 |  |
Greens Creek [Member] |  |  |  |  |  |  |  |  |  |
Open Purchase Orders |  |  |  |  | 5,500 |  |  | 5,500 |  |
Nevada Operations [Member] |  |  |  |  |  |  |  |  |  |
Open Purchase Orders |  |  |  |  | $ 4,700 |  |  | $ 4,700 |  |
Johnny M Mine Area near San Mateo, New Mexico [Member] |  |  |  |  |  |  |  |  |  |
Payment Of Response Costs |  | $ 1,100 | $ 1,100 |  |  |  |  |  |  |
Estimated Response Costs | $ 9,600 |  |  |  |  | $ 9,000 |  |  |  | $ 6,100
Environmental Remediation Expense |  |  |  |  |  | $ 9,000 |  |  |  |
Carpenter Snow Creek Superfund Site, Cascade County, Montana [Member] |  |  |  |  |  |  |  |  |  |
Estimated Response Costs |  |  |  | $ 4,500 |  |  |  |  |  |
Estimated Future Response Cost |  |  |  | $ 100,000 |  |  |  |  |  |

X
- Definition Represents the estimated future response cost that the EPA may ultimately incur related to a site. + References No definition available. + Details
Name: | hl_EstimatedFutureResponseCost
Namespace Prefix: | hl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the estimated amount of response costs that have been incurred by the EPA in cleaning up a site. + References No definition available. + Details
Name: | hl_EstimatedResponseCosts
Namespace Prefix: | hl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the amount of open purchase orders as of a specified date. + References No definition available. + Details
Name: | hl_OpenPurchaseOrders
Namespace Prefix: | hl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Represents the amount of response costs paid during the period. + References No definition available. + Details
Name: | hl_PaymentOfResponseCosts
Namespace Prefix: | hl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Represents the amount of surety bonds in place as of a specified date. Such surety bonds may be for the purpose of, but not limited to, financial support for future reclamation and closure costs, self-insurance, and employee benefit plans. + References No definition available. + Details
Name: | hl_SuretyBonds
Namespace Prefix: | hl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments. + References No definition available. + Details
Name: | us-gaap_ContractualObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109237650&loc=d3e13064-110858 Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 12 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13296-110859 + Details
Name: | us-gaap_EnvironmentalRemediationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of lessee's undiscounted obligation for lease payments for finance lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=123408670&loc=SL77918701-209980 + Details
Name: | us-gaap_FinanceLeaseLiabilityPaymentsDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of lessee's undiscounted obligation for lease payment for operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=123408670&loc=SL77918701-209980 + Details
Name: | us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_OtherCommitmentsAxis=hl_PerformanceObligationCommitmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=hl_LuckyFridayMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=hl_CasaBerardiMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=hl_GreensCreekMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=hl_NevadaOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnvironmentalRemediationSiteAxis=hl_JohnnyMMineAreaNearSanMateoNewMexicoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnvironmentalRemediationSiteAxis=hl_CarpenterSnowCreekSuperfundSiteCascadeCountyMontanaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |