Note 16 - Guarantor Subsidiaries (Details Textual) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2015
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	100.00%
Hecla Limited [Member]
Sale of Stock, Percentage of Ownership before Transaction		100.00%
Proceeds from Divestiture of Businesses		$ 240.8
Capital Requirements, Limited Funding Period		5 years
Hecla Alaska LLC [Member] \| Greens Creek [Member]
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	29.7331%

Represents the limited amount funding of capital requirements.

No definition available.

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- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

+ Details

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- Definition

Percentage of subsidiary's or equity investee's stock owned by parent company before stock transaction.

+ References

No definition available.

+ Details

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- Definition

Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.

+ References

No definition available.

+ Details

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- Details

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- Details

Name:	dei_LegalEntityAxis=hl_HeclaAlaskaLLCMember
Namespace Prefix:
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- Details

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