XML 120 R89.htm IDEA: XBRL DOCUMENT
v3.20.4

Note 15 - Accumulated Other Comprehensive Loss (Details Textual) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 USD ($)
Impact of Adoption of Accounting Standard Update | $ 0
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] |
Impact of Adoption of Accounting Standard Update | $ (1,300)

X
- Definition Represents the reclassification from retained earnings to AOCI during the period related to the adoption of an accounting standards update. + References No definition available. + Details
Name: | hl_ImpactOfAdoptionOfAccountingStandardUpdate
Namespace Prefix: | hl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |