Note 1 - Basis of Preparation of Financial Statements	6 Months Ended
Jun. 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 six-month periods ended June 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. In addition, we incurred costs of approximately $1.0 million in the first half of 2021 and $2.3 million for the full year of 2020 related to quarantining employees at Greens Creek, which started in late March 2020, and incurred costs of approximately $1.2 million in the first half of 2021 related to COVID-19 procedures at Casa Berardi. 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 half 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 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. Correction of an Immaterial Error During the first quarter of 2021 we reclassified certain state mining income taxes from Cost of sales and other direct production costs to Income and mining tax provision prospectively effective January 1, 2021. The reclassification required us to recognize previously unrecognized deferred taxes. The impact of this was an adjustment of $11.9 million to accumulated deficit at January 1, 2019 to recognize the deferred tax liability. This adjustment resulted in the January 1, 2020 accumulated deficit balance presented in this Form 10-Q increasing to $365.2 million.

Note 1 - Basis of Preparation of Financial Statements

6 Months Ended

Jun. 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 six-month periods ended June 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. In addition, we incurred costs of approximately $1.0 million in the first half of 2021 and $2.3 million for the full year of 2020 related to quarantining employees at Greens Creek, which started in late March 2020, and incurred costs of approximately $1.2 million in the first half of 2021 related to COVID-19 procedures at Casa Berardi. 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 half 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 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.

Correction of an Immaterial Error

During the first quarter of 2021 we reclassified certain state mining income taxes from Cost of sales and other direct production costs to Income and mining tax provision prospectively effective January 1, 2021. The reclassification required us to recognize previously unrecognized deferred taxes. The impact of this was an adjustment of $11.9 million to accumulated deficit at January 1, 2019 to recognize the deferred tax liability. This adjustment resulted in the January 1, 2020 accumulated deficit balance presented in this Form 10-Q increasing to $365.2 million.