Note 8 - Employee Benefit Plans - Employee Allocations of Investments and Measurement Dates by Asset Category (Details)	Dec. 31, 2016	Dec. 31, 2015
Hecla Mining Company Retirement Plan [Member]
Allocation of investments	100.00%	100.00%
Lucky Friday Pension Plan [Member]
Allocation of investments	100.00%	100.00%
Cash [Member] | Hecla Mining Company Retirement Plan [Member]
Allocation of investments	3.00%	2.00%
Cash [Member] | Lucky Friday Pension Plan [Member]
Allocation of investments	3.00%	4.00%
Large Cap US Equity [Member] | Hecla Mining Company Retirement Plan [Member]
Allocation of investments	18.00%	10.00%
Large Cap US Equity [Member] | Lucky Friday Pension Plan [Member]
Allocation of investments	17.00%	10.00%
Small Cap US Equity [Member] | Hecla Mining Company Retirement Plan [Member]
Allocation of investments	9.00%	5.00%
Small Cap US Equity [Member] | Lucky Friday Pension Plan [Member]
Allocation of investments	9.00%	5.00%
Foreign Government Debt Securities [Member] | Hecla Mining Company Retirement Plan [Member]
Allocation of investments	24.00%	9.00%
Foreign Government Debt Securities [Member] | Lucky Friday Pension Plan [Member]
Allocation of investments	25.00%	9.00%
Fixed Income Funds [Member] | Hecla Mining Company Retirement Plan [Member]
Allocation of investments	20.00%	34.00%
Fixed Income Funds [Member] | Lucky Friday Pension Plan [Member]
Allocation of investments	20.00%	33.00%
Real Estate [Member] | Hecla Mining Company Retirement Plan [Member]
Allocation of investments	13.00%	18.00%
Real Estate [Member] | Lucky Friday Pension Plan [Member]
Allocation of investments	13.00%	18.00%
Hedge Funds [Member] | Hecla Mining Company Retirement Plan [Member]
Allocation of investments	6.00%	15.00%
Hedge Funds [Member] | Lucky Friday Pension Plan [Member]
Allocation of investments	6.00%	14.00%
Real Return [Member] | Hecla Mining Company Retirement Plan [Member]
Allocation of investments		1.00%
Real Return [Member] | Lucky Friday Pension Plan [Member]
Allocation of investments		1.00%
Common Stock [Member] | Hecla Mining Company Retirement Plan [Member]
Allocation of investments	7.00%	6.00%
Common Stock [Member] | Lucky Friday Pension Plan [Member]
Allocation of investments	7.00%	6.00%