XML 34 R53.htm IDEA: XBRL DOCUMENT
v3.19.3

Note 11 - Derivative Instruments - Summary of Forward Sales and Put Option Contracts (Details) oz in Thousands, lb in Thousands | 6 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2019 USD ($) oz | Sep. 30, 2019 USD ($) lb oz | Dec. 31, 2018 USD ($) lb oz
Silver 2019 Settlements for Provisional Sales [Member] |  |  |
Ounces/pounds under contract (Ounce) | oz |  | 828 | 842
Average price per ounce/pound |  | $ 18.66 | $ 14.69
Gold 2019 Settlements for Provisional Sales [Member] |  |  |
Ounces/pounds under contract (Ounce) | oz |  | 3 | 4
Average price per ounce/pound |  | $ 1,537 | $ 1,260
Zinc 2019 Settlements for Provisional Sales [Member] |  |  |
Ounces/pounds under contract (Ounce) | lb |  | 16,204 |
Average price per ounce/pound |  | $ 1.09 |
Lead 2019 Settlements for Provisional Sales [Member] |  |  |
Ounces/pounds under contract (Ounce) | lb |  | 2,921 | 2,700
Average price per ounce/pound |  | $ 0.90 | $ 0.89
Zinc 2018 Settlements for Provisional Sales [Member] |  |  |
Ounces/pounds under contract (Ounce) | lb |  |  | 18,450
Average price per ounce/pound |  |  | $ 1.15
Put Option Contract for Silver 1 [Member] |  |  |
Ounces/pounds under contract (Ounce) | oz |  | 2,493 |
Average price per ounce/pound |  | $ 15.08 |
Put Option Contract for Gold 1 [Member] |  |  |
Ounces/pounds under contract (Ounce) | oz |  | 89 |
Average price per ounce/pound |  | $ 1,400 |
Lead 2019 Settlements for Forecasted Sales [Member] |  |  |
Ounces/pounds under contract (Ounce) | lb |  | 4,409 |
Average price per ounce/pound |  | $ 0.95 |
Put Option Contract for Silver 2 [Member] |  |  |
Ounces/pounds under contract (Ounce) | oz |  | 2,634 |
Average price per ounce/pound |  | $ 15.00 |
Put Option Contract for Gold 2 [Member] |  |  |
Ounces/pounds under contract (Ounce) | oz |  | 51 |
Average price per ounce/pound |  | $ 1,400 |
Lead 2020 Settlements for Forecasted Sales [Member] |  |  |
Ounces/pounds under contract (Ounce) | oz | 4,960 |  |
Average price per ounce/pound | $ 960 |  |

X
- Definition The average price per ounce/pound. + References No definition available. + Details
Name: | hl_AveragePricePerOuncePound
Namespace Prefix: | hl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Nominal mass used to calculate payments on a derivative instrument. + References No definition available. + Details
Name: | us-gaap_DerivativeNonmonetaryNotionalAmountMass
Namespace Prefix: | us-gaap_
Data Type: | num:massItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_Silver2019SettlementsForProvisionalSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_Gold2019SettlementsForProvisionalSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_Zinc2019SettlementsForProvisionalSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_Lead2019SettlementsForProvisionalSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_Zinc2018SettlementsForProvisionalSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_PutOptionContractForSilver1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_PutOptionContractForGold1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_Lead2019SettlementsForForecastedSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_PutOptionContractForSilver2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_PutOptionContractForGold2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=hl_Lead2020SettlementsForForecastedSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |