XML 34 R53.htm IDEA: XBRL DOCUMENT v3.19.3

Note 11 - Derivative Instruments - Summary of Forward Sales and Put Option Contracts (Details) oz in Thousands, lb in Thousands	6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2019 USD ($) oz	Sep. 30, 2019 USD ($) lb oz	Dec. 31, 2018 USD ($) lb oz
Silver 2019 Settlements for Provisional Sales [Member]
Ounces/pounds under contract (Ounce) | oz		828	842
Average price per ounce/pound		$ 18.66	$ 14.69
Gold 2019 Settlements for Provisional Sales [Member]
Ounces/pounds under contract (Ounce) | oz		3	4
Average price per ounce/pound		$ 1,537	$ 1,260
Zinc 2019 Settlements for Provisional Sales [Member]
Ounces/pounds under contract (Ounce) | lb		16,204
Average price per ounce/pound		$ 1.09
Lead 2019 Settlements for Provisional Sales [Member]
Ounces/pounds under contract (Ounce) | lb		2,921	2,700
Average price per ounce/pound		$ 0.90	$ 0.89
Zinc 2018 Settlements for Provisional Sales [Member]
Ounces/pounds under contract (Ounce) | lb			18,450
Average price per ounce/pound			$ 1.15
Put Option Contract for Silver 1 [Member]
Ounces/pounds under contract (Ounce) | oz		2,493
Average price per ounce/pound		$ 15.08
Put Option Contract for Gold 1 [Member]
Ounces/pounds under contract (Ounce) | oz		89
Average price per ounce/pound		$ 1,400
Lead 2019 Settlements for Forecasted Sales [Member]
Ounces/pounds under contract (Ounce) | lb		4,409
Average price per ounce/pound		$ 0.95
Put Option Contract for Silver 2 [Member]
Ounces/pounds under contract (Ounce) | oz		2,634
Average price per ounce/pound		$ 15.00
Put Option Contract for Gold 2 [Member]
Ounces/pounds under contract (Ounce) | oz		51
Average price per ounce/pound		$ 1,400
Lead 2020 Settlements for Forecasted Sales [Member]
Ounces/pounds under contract (Ounce) | oz	4,960
Average price per ounce/pound	$ 960

X

- Definition

The average price per ounce/pound.

+ References

No definition available.

+ Details

Name:	hl_AveragePricePerOuncePound
Namespace Prefix:	hl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Nominal mass used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeNonmonetaryNotionalAmountMass
Namespace Prefix:	us-gaap_
Data Type:	num:massItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_Silver2019SettlementsForProvisionalSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_Gold2019SettlementsForProvisionalSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_Zinc2019SettlementsForProvisionalSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_Lead2019SettlementsForProvisionalSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_Zinc2018SettlementsForProvisionalSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_PutOptionContractForSilver1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_PutOptionContractForGold1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_Lead2019SettlementsForForecastedSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_PutOptionContractForSilver2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_PutOptionContractForGold2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hl_Lead2020SettlementsForForecastedSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: