Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 16, 2021	Jun. 30, 2020
Document Information [Line Items]
Entity Central Index Key	0000719413
Entity Registrant Name	HECLA MINING CO/DE/
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2020
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
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			$ 1,705,927,032
Entity Common Stock, Shares Outstanding		535,187,791
Series B Cumulative Preferred Stock [Member]
Document Information [Line Items]
Title of 12(b) Security	Series B Cumulative Convertible Preferred Stock, par value $0.25 per share
Trading Symbol	HL-PB
Security Exchange Name	NYSE
Common Stock [Member]
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.25 per share
Trading Symbol	HL
Security Exchange Name	NYSE