Note 8 - Employee Benefit Plans - Fair Value by Asset Category (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Hecla Mining Company Retirement Plan [Member]
Total fair value	$ 68,684	$ 57,673
Hecla Mining Company Retirement Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value	45,223	33,023
Hecla Mining Company Retirement Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value	12,379	9,862
Hecla Mining Company Retirement Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value	11,082	14,788
Hecla Mining Company Retirement Plan [Member] | Interest-bearing Deposits [Member]
Total fair value	1,924	936
Hecla Mining Company Retirement Plan [Member] | Interest-bearing Deposits [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value	1,924	936
Hecla Mining Company Retirement Plan [Member] | Interest-bearing Deposits [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value
Hecla Mining Company Retirement Plan [Member] | Interest-bearing Deposits [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value
Hecla Mining Company Retirement Plan [Member] | Common Stock [Member]
Total fair value	4,973	3,284
Hecla Mining Company Retirement Plan [Member] | Common Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value	4,973	3,284
Hecla Mining Company Retirement Plan [Member] | Common Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value
Hecla Mining Company Retirement Plan [Member] | Common Stock [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value
Hecla Mining Company Retirement Plan [Member] | Real Estate Investments [Member]
Total fair value	8,974	10,326
Hecla Mining Company Retirement Plan [Member] | Real Estate Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value
Hecla Mining Company Retirement Plan [Member] | Real Estate Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value
Hecla Mining Company Retirement Plan [Member] | Real Estate Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value	8,974	10,326
Hecla Mining Company Retirement Plan [Member] | Common Collective Funds [Member]
Total fair value	14,487	14,324
Hecla Mining Company Retirement Plan [Member] | Common Collective Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value
Hecla Mining Company Retirement Plan [Member] | Common Collective Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value	12,379	9,862
Hecla Mining Company Retirement Plan [Member] | Common Collective Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value	2,108	4,462
Hecla Mining Company Retirement Plan [Member] | Mutual Funds [Member]
Total fair value	38,326	28,803
Hecla Mining Company Retirement Plan [Member] | Mutual Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value	38,326	28,803
Hecla Mining Company Retirement Plan [Member] | Mutual Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value
Hecla Mining Company Retirement Plan [Member] | Mutual Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value
Lucky Friday Pension Plan [Member]
Total fair value	18,673	15,648
Lucky Friday Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value	12,307	8,910
Lucky Friday Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value	3,427	2,573
Lucky Friday Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value	2,939	4,165
Lucky Friday Pension Plan [Member] | Interest-bearing Deposits [Member]
Total fair value	550	76
Lucky Friday Pension Plan [Member] | Interest-bearing Deposits [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value	550	76
Lucky Friday Pension Plan [Member] | Interest-bearing Deposits [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value
Lucky Friday Pension Plan [Member] | Interest-bearing Deposits [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value
Lucky Friday Pension Plan [Member] | Common Stock [Member]
Total fair value	1,340	989
Lucky Friday Pension Plan [Member] | Common Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value	1,340	989
Lucky Friday Pension Plan [Member] | Common Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value
Lucky Friday Pension Plan [Member] | Common Stock [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value
Lucky Friday Pension Plan [Member] | Real Estate Investments [Member]
Total fair value	2,389	2,856
Lucky Friday Pension Plan [Member] | Real Estate Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value
Lucky Friday Pension Plan [Member] | Real Estate Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value
Lucky Friday Pension Plan [Member] | Real Estate Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value	2,389	2,856
Lucky Friday Pension Plan [Member] | Common Collective Funds [Member]
Total fair value	3,977	3,882
Lucky Friday Pension Plan [Member] | Common Collective Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value
Lucky Friday Pension Plan [Member] | Common Collective Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value	3,427	2,573
Lucky Friday Pension Plan [Member] | Common Collective Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value	550	1,309
Lucky Friday Pension Plan [Member] | Mutual Funds [Member]
Total fair value	10,417	7,845
Lucky Friday Pension Plan [Member] | Mutual Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Total fair value	10,417	7,845
Lucky Friday Pension Plan [Member] | Mutual Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Total fair value
Lucky Friday Pension Plan [Member] | Mutual Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Total fair value