XML 77 R38.htm IDEA: XBRL DOCUMENT
v3.3.0.814

Note 7 - Employee Benefit Plans (Details) - USD ($) $ in Millions | 1 Months Ended | 8 Months Ended | 9 Months Ended
--- | --- | --- | ---
Jan. 31, 2015 | Sep. 30, 2015 | Sep. 30, 2015
Pension Plan [Member] |  |  |
Note 7 - Employee Benefit Plans (Details) [Line Items] |  |  |
Defined Benefit Plan, Contributions by Employer | $ 5.0 |  |
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year |  | $ 0.0 |
Unfunded Supplemental Executive Retirement Plan [Member] |  |  |
Note 7 - Employee Benefit Plans (Details) [Line Items] |  |  |
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year |  |  | $ 0.4

X
- References No definition available. + Details
Name: | hl_Note7EmployeeBenefitPlansDetailsLineItems
Namespace Prefix: | hl_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The increase in the fair value of plan assets from contributions made by the employer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of employer's best estimate of contributions expected to be paid to the plan in the current remaining fiscal period. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=hl_UnfundedSupplementalExecutiveRetirementPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |