Note 1 - Basis of Preparation of Financial Statements	9 Months Ended
Sep. 30, 2021
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]	Note 1. Basis of Preparation of Financial Statements The accompanying unaudited interim condensed consolidated financial statements of Hecla Mining Company and its subsidiaries (collectively, “Hecla,” “the Company,” “we,” “our,” or “us,” except where the context requires otherwise) have been prepared in accordance with the instructions to Form 10-Q and do not include all information and disclosures required annually by generally accepted accounting principles in the United States (“GAAP”). Therefore, this information should be read in conjunction with Hecla Mining Company’s consolidated financial statements and notes contained in our annual report on Form 10-K for the year ended December 31, 2020 (“2020 Form 10-K”). The consolidated December 31, 2020 balance sheet data was derived from our audited consolidated financial statements. The information furnished herein reflects all adjustments that are, in the opinion of management, necessary for a fair statement of the results for the interim periods reported. All such adjustments are, in the opinion of management, of a normal recurring nature. Operating results for the three- and nine-month periods ended September 30, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021. The 2019 novel strain of coronavirus (“COVID-19”) was characterized as a global pandemic by the World Health Organization on March 11, 2020, and COVID-19 resulted in travel restrictions and business slowdowns or shutdowns in affected areas. In late March 2020, the Government of Quebec ordered the mining industry to reduce to minimum operations as part of the fight against COVID-19, causing us to suspend our Casa Berardi operations from March 24, 2020 until April 15, 2020 when mining operations resumed. In early April 2020, the Government of Mexico issued a similar order causing us to suspend our San Sebastian operations until May 30, 2020. In addition, restrictions imposed by the State of Alaska in late March 2020 caused us to revise the normal operating procedures for staffing operations at Greens Creek. These suspension orders impacted us in the first half of 2020 by curtailing our expected production of gold at Casa Berardi by approximately 11,700 ounces, which resulted in a reduction in related revenue for that period. We continued to incur costs at Casa Berardi and San Sebastian while operations were suspended. At Casa Berardi and San Sebastian, suspension costs in 2020 totaled $1.6 million and $1.8 million, respectively. At Greens Creek, we incurred costs of approximately $1.0 million in the first nine months of 2021 and $2.3 million for the full year of 2020 related to quarantining employees from late March 2020 through the second quarter of 2021. In addition, silver production at Greens Creek in the third quarter of 2021 was 30% lower than in the third quarter of 2020 due to reduced ore grades as a result of mine sequencing, which was impacted by manpower challenges due to COVID-19 and increased competition for labor which we expect to mitigate through schedule changes and other means. At Casa Berardi, we incurred costs of approximately $1.9 million in the first nine months of 2021 related to COVID-19 procedures. At the Lucky Friday, San Sebastian and Nevada Operations units, COVID-19 procedures have been implemented without a significant impact on operating or suspension costs or production. It is possible that future restrictions at any of our operations could have an adverse impact on operations or financial results beyond the first nine months of 2021. We have taken precautionary measures to mitigate the impact of COVID-19, including implementing operational plans and practices. As long as they are required, the operational practices implemented could continue to have an adverse impact on our operating results due to deferred production and revenues or additional costs. We continue to monitor the rapidly evolving situation and guidance from federal, state, local and foreign governments and public health authorities and may take additional actions based on their recommendations. The extent of the impact of COVID-19 on our business and financial results will also depend on future developments, including the duration and spread of the outbreak and the success of the current vaccination programs being rolled out within the markets in which we operate and the related impact on prices, demand, creditworthiness and other market conditions and governmental reactions, all of which are highly uncertain. In the third quarter of 2021, we identified errors impacting amounts reported for accumulated depreciation, depletion and amortization ("DDA") and DDA expense for our Casa Berardi unit from June 1, 2013 through June 30, 2021. Certain amounts in the condensed consolidated financial statements and notes thereto for the prior period have been revised to correct these errors. See Note 2 for more information on the errors and revisions made to amounts reported for the prior periods.

Note 1 - Basis of Preparation of Financial Statements

9 Months Ended

Sep. 30, 2021

Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]

Note 1. Basis of Preparation of Financial Statements

The accompanying unaudited interim condensed consolidated financial statements of Hecla Mining Company and its subsidiaries (collectively, “Hecla,” “the Company,” “we,” “our,” or “us,” except where the context requires otherwise) have been prepared in accordance with the instructions to Form 10-Q and do not include all information and disclosures required annually by generally accepted accounting principles in the United States (“GAAP”). Therefore, this information should be read in conjunction with Hecla Mining Company’s consolidated financial statements and notes contained in our annual report on Form 10-K for the year ended December 31, 2020 (“2020 Form 10-K”). The consolidated December 31, 2020 balance sheet data was derived from our audited consolidated financial statements. The information furnished herein reflects all adjustments that are, in the opinion of management, necessary for a fair statement of the results for the interim periods reported. All such adjustments are, in the opinion of management, of a normal recurring nature. Operating results for the three- and nine-month periods ended September 30, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021.

The 2019 novel strain of coronavirus (“COVID-19”) was characterized as a global pandemic by the World Health Organization on March 11, 2020, and COVID-19 resulted in travel restrictions and business slowdowns or shutdowns in affected areas. In late March 2020, the Government of Quebec ordered the mining industry to reduce to minimum operations as part of the fight against COVID-19, causing us to suspend our Casa Berardi operations from March 24, 2020 until April 15, 2020 when mining operations resumed. In early April 2020, the Government of Mexico issued a similar order causing us to suspend our San Sebastian operations until May 30, 2020. In addition, restrictions imposed by the State of Alaska in late March 2020 caused us to revise the normal operating procedures for staffing operations at Greens Creek. These suspension orders impacted us in the first half of 2020 by curtailing our expected production of gold at Casa Berardi by approximately 11,700 ounces, which resulted in a reduction in related revenue for that period. We continued to incur costs at Casa Berardi and San Sebastian while operations were suspended. At Casa Berardi and San Sebastian, suspension costs in 2020 totaled $1.6 million and $1.8 million, respectively. At Greens Creek, we incurred costs of approximately $1.0 million in the first nine months of 2021 and $2.3 million for the full year of 2020 related to quarantining employees from late March 2020 through the second quarter of 2021. In addition, silver production at Greens Creek in the third quarter of 2021 was 30% lower than in the third quarter of 2020 due to reduced ore grades as a result of mine sequencing, which was impacted by manpower challenges due to COVID-19 and increased competition for labor which we expect to mitigate through schedule changes and other means. At Casa Berardi, we incurred costs of approximately $1.9 million in the first nine months of 2021 related to COVID-19 procedures. At the Lucky Friday, San Sebastian and Nevada Operations units, COVID-19 procedures have been implemented without a significant impact on operating or suspension costs or production. It is possible that future restrictions at any of our operations could have an adverse impact on operations or financial results beyond the first nine months of 2021.

We have taken precautionary measures to mitigate the impact of COVID-19, including implementing operational plans and practices. As long as they are required, the operational practices implemented could continue to have an adverse impact on our operating results due to deferred production and revenues or additional costs. We continue to monitor the rapidly evolving situation and guidance from federal, state, local and foreign governments and public health authorities and may take additional actions based on their recommendations. The extent of the impact of COVID-19 on our business and financial results will also depend on future developments, including the duration and spread of the outbreak and the success of the current vaccination programs being rolled out within the markets in which we operate and the related impact on prices, demand, creditworthiness and other market conditions and governmental reactions, all of which are highly uncertain.

In the third quarter of 2021, we identified errors impacting amounts reported for accumulated depreciation, depletion and amortization ("DDA") and DDA expense for our Casa Berardi unit from June 1, 2013 through June 30, 2021. Certain amounts in the condensed consolidated financial statements and notes thereto for the prior period have been revised to correct these errors. See Note 2 for more information on the errors and revisions made to amounts reported for the prior periods.