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v3.22.1

Note 1 - Basis of Preparation of Financial Statements (Details Textual) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2022 | Mar. 31, 2021
COVID-19 Mitigation Costs | $ 0.4 | $ 1.6

X
- Definition Information on costs incurred related to mitigating the effect of COVID-19 mitigation. + References No definition available. + Details
Name: | hl_COVID19MitigationCosts
Namespace Prefix: | hl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration