Note 15 - Acquisitions - Preliminary Purchase Price Allocation (Details) - USD ($) $ in Thousands	Sep. 13, 2016	Jun. 15, 2015	Jun. 30, 2015
Mines Management [Member]
Cash	$ 4,025
Hecla stock issued (8,309,006 shares at $5.79 per share)	48,109
Total consideration	52,134
Cash	94
Property, plants, equipment and mineral interests	68,038
Restricted cash	1,185
Other assets	329
Total assets	69,646
Accounts payable and accrued liabilities	2,357
Deferred tax liability	14,031
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Reclamation Liability	1,124
Total liabilities	17,512
Net assets	52,134
Payments to Acquire Businesses, Gross	4,025
Hecla stock issued (6,252,646 shares at $3.06 per share)	48,109
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	$ 68,038
Revett Mining Company, Inc. [Member]
Cash		$ 949
Hecla stock issued (8,309,006 shares at $5.79 per share)		19,133
Total consideration		20,082
Cash		140
Property, plants, equipment and mineral interests		17,609
Other assets		280
Total assets		42,631
Accounts payable and accrued liabilities		975
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Reclamation Liability		17,513	$ 17,500
Total liabilities		22,549
Net assets		20,082
Payments to Acquire Businesses, Gross		949
Hecla stock issued (6,252,646 shares at $3.06 per share)		19,133
Accounts receivable		137
Inventory - supplies		472
Deferred tax assets		7,193
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		17,609
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Reclamation Insurance Asset		16,800	$ 16,800
Notes payable		$ 4,061