XML 115 R85.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Note 11 - Business Segments and Significant Customers - Sales from Continuing Operations to Significant Metals Customers As a Percentage of Total Sales (Details) - Sales Revenue, Goods, Net [Member] - Customer Concentration Risk [Member] | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Teck Metals Ltd [Member] |  |  |
Significant metal customers | 11.30% | 21.20% | 22.50%
Korea Zinc [Member] |  |  |
Significant metal customers | 16.40% | 16.90% | 16.00%
Scotia [Member] |  |  |
Significant metal customers | 24.90% | 24.50% | 5.60%
CIBC [Member] |  |  |
Significant metal customers | 22.80% | 19.00% | 17.60%
Mitsui [Member] |  |  |
Significant metal customers | 7.60% | 4.40% | 10.20%

X
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611 + Details
Name: | us-gaap_ConcentrationRiskPercentage1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueGoodsNetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=hl_TeckMetalsLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=hl_KoreaZincMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=hl_ScotiaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=hl_CIBCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=hl_MitsuiMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |