Note 8 - Derivative Instruments (Tables)

3 Months Ended

Mar. 31, 2023

Table Text Block [Abstract]

Schedule of Foreign Exchange Contracts, Statement of Financial Position [Table Text Block]

fair value of the contracts (in millions):

	March 31,		December 31,
Balance sheet line item:	2023		2022
Other current assets	$	1.6	$	1.1
Other non-current assets		0.8		0.4
Current derivative liabilities		3.6		4.0
Non-current derivative liabilities	$	3.1	$	3.6

Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]

The following tables summarize the quantities of metals committed under forward sales contracts at March 31, 2023 and December 31, 2022:

March 31, 2023	Ounces/pounds under contract (in 000's)								Average price per ounce/pound
	Silver		Gold		Zinc		Lead		Silver		Gold		Zinc		Lead
	(ounces)		(ounces)		(pounds)		(pounds)		(ounces)		(ounces)		(pounds)		(pounds)
Contracts on provisional sales
2023 settlements		3,350		8		15,543		18,133	$	22.27	$	1,883	$	1.35	$	1.01
Contracts on forecasted sales
2023 settlements		—		—		29,873		38,581		—		—	$	1.47	$	1.00
2024 settlements		—		—		1,764		75,178		—		—		1.31	$	0.98
2025 settlements		—		—		—		882	$	—	$	—	$	—	$	0.97

December 31, 2022	Ounces/pounds under contract (in 000's)								Average price per ounce/pound
	Silver		Gold		Zinc		Lead		Silver		Gold		Zinc		Lead
	(ounces)		(ounces)		(pounds)		(pounds)		(ounces)		(ounces)		(pounds)		(pounds)
Contracts on provisional sales
2023 settlements		3,124		8		18,629		11,960	$	21.55	$	1,795	$	1.38	$	0.98
Contracts on forecasted sales
2023 settlements		—		—		37,533		75,618	N/A		N/A		$	1.34	$	1.00
2024 settlements		—		—		—		45,856	N/A		N/A		N/A		$	0.99

Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block]

We recorded the following balances for the fair value of the forward contracts as of March 31, 2023 and December 31, 2022 (in millions):

	March 31, 2023								December 31, 2022
Balance sheet line item:	Contracts in an asset position		Contracts in a liability position			Net asset (liability)			Contracts in an asset position		Contracts in a liability position			Net asset (liability)
Other current assets	$	5.3	$	—		$	5.3		$	1.2	$	—		$	1.2
Other non-current assets	$	1.3	$	—		$	1.3		$	0.1	$	—		$	0.1
Current derivative liabilities		—		(4.6	)		(4.6	)		—		(12.1	)		(12.1	)
Non-current derivative liabilities		—		(0.05	)		(0.1	)		—		(2.5	)		(2.5	)