Document And Entity Information - USD ($)	Dec. 31, 2019	Feb. 06, 2020	Jun. 30, 2019
Document Information [Line Items]
Entity, Registrant Name	HECLA MINING COMPANY
Current Fiscal Year End Date	--12-31
Document, Fiscal Period Focus	FY
Document, Fiscal Year Focus	2019
Document, Type	10-K/A
Document, Annual Report	true
Document, Period End Date	Dec. 31, 2019
Document, Transition Report	false
Entity, File Number	1-8491
Entity, Incorporation, State or Country Code	DE
Entity, Tax Identification Number	77-0664171
Entity, Address, Address Line One	6500 N. Mineral Drive, Suite 200
Entity, Address, City or Town	Coeur d’Alene
Entity, Address, State or Province	ID
Entity, Address, Postal Zip Code	83815-9408
City Area Code	208
Local Phone Number	769-4100
Entity, Well-known Seasoned Issuer	Yes
Entity, Voluntary Filers	No
Entity, Current Reporting Status	Yes
Entity, Interactive Data, Current	Yes
Entity, Filer Category	Large Accelerated Filer
Entity, Small Business	false
Entity, Emerging Growth Company	false
Entity, Shell Company	false
Entity, Public Float			$ 868,456,633
Entity, Common Stock Shares, Outstanding		523,216,426
Amendment Description	This Amendment No. 1 to Form 10-K (this “Amendment”) amends the Annual Report on Form 10-K for the fiscal year ended December 31, 2019, originally filed by Hecla Mining Company (the “Company”) on February 10, 2020 (the “Original Filing”). Due to a clerical error, the Company reported an incorrect number of shares outstanding on the cover page of the Original Filing. This Amendment corrects the number of shares outstanding on the cover page and updates Item 15 of Part II of the Original Filing to reflect the additions of Exhibits 31.3 and 31.4, which are filed with this Amendment. Except as described in this Explanatory Note, no other changes have been made to the Original Filing. The Original Filing continues to speak as of its filing date, and we otherwise have not updated the Original Filing to reflect any events which occurred subsequent to the filing date of the Original Filing.
Amendment Flag	true
Entity, Central Index Key	0000719413
CommonStock Custom [Member]
Document Information [Line Items]
Title of 12(b) Security	Common Stock
Trading Symbol	HL
Security Exchange Name	NYSE
SeriesBCumulativeConvertiblePreferredStock Custom [Member]
Document Information [Line Items]
Title of 12(b) Security	Series B Cumulative Convertible Preferred Stock
Trading Symbol	HL-PB
Security Exchange Name	NYSE