Note 9 - Debt, Credit Facility and Leases (Details Textual) $ in Thousands, $ in Millions				12 Months Ended
	Feb. 16, 2026	Jul. 21, 2022	Mar. 19, 2020 USD ($)	Feb. 15, 2026	Dec. 31, 2025 USD ($)	Feb. 15, 2025	Dec. 31, 2024 USD ($)	Feb. 15, 2024	Dec. 31, 2023 USD ($)	Dec. 31, 2021	May 03, 2024 USD ($)	Jul. 09, 2020 USD ($)	Jul. 09, 2020 CAD ($)	Feb. 19, 2020 USD ($)
Proceeds from issuance of long-term debt					$ 153,000		$ 279,000		$ 239,000
Finance lease liability					13,853		21,900
Finance lease liability, current					7,200		8,200
Finance lease liability, noncurrent					6,700		13,700
Finance lease right-of-use asset					7,400		14,000
Finance lease right-of-use asset, amortization					7,200		7,900		12,600
Finance lease, interest expense					800		$ 900		900
Finance lease, liability, payment, due					14,924
Finance lease, liability, undiscounted excess amount					$ 1,071
Finance lease, weighted average remaining lease term (year)					1 year 9 months 18 days		1 year 8 months 12 days
Finance lease, weighted average discount rate, percent					8.30%		9.70%
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]					Liabilities		Liabilities
Finance lease, right-of-use asset, statement of financial position [Extensible Enumeration]					Properties, plants, equipment and mine development, net		Properties, plants, equipment and mine development, net
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]					Liabilities, Current		Liabilities, Current
Operating lease liability					$ 9,294		$ 8,000
Operating lease liability, current					1,100		900
Operating lease liability, noncurrent					8,200		7,100
Operating lease right-of-use asset					8,859		7,544
Operating lease expense					$ 3,800		$ 3,800		3,100
Operating lease, weighted average remaining lease term (year)					6 years 1 month 6 days		7 years 3 months 18 days
Operating lease, weighted average discount rate, percent					5.50%		5.70%
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]					Liabilities, Current		Liabilities, Current
IQ Notes [Member]
Debt instrument total payment					$ 34,700
New Credit Agreement [Member]
Line of credit facility, maximum borrowing capacity					218,300
Long-term line of credit					$ 6,700		$ 6,200
Proceeds from lines of credit							23,000
New Credit Agreement [Member] | Revolving Credit Facility [Member] | Minimum [Member]
Line of credit facility, maximum borrowing capacity											$ 150,000
Line of credit facility, commitment fee percentage		0.45%
New Credit Agreement [Member] | Revolving Credit Facility [Member] | Maximum [Member]
Line of credit facility, maximum borrowing capacity											$ 225,000
Line of credit facility, commitment fee percentage		0.7875%
New Credit Agreement [Member] | Revolving Credit Facility [Member] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] | Minimum [Member]
Debt instrument, basis spread on variable rate					2.00%
New Credit Agreement [Member] | Revolving Credit Facility [Member] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] | Maximum [Member]
Debt instrument, basis spread on variable rate					3.50%
New Credit Agreement [Member] | Revolving Credit Facility [Member] | Base Rate [Member] | Minimum [Member]
Debt instrument, basis spread on variable rate					1.00%
Debt instrument, basis spread on variable rate, applicable margin		1.00%
New Credit Agreement [Member] | Revolving Credit Facility [Member] | Base Rate [Member] | Maximum [Member]
Debt instrument, basis spread on variable rate					2.50%
New Credit Agreement [Member] | Revolving Credit Facility [Member] | Fed Funds Effective Rate Overnight Index Swap Rate [Member]
Debt instrument, basis spread on variable rate		0.50%
New Credit Agreement [Member] | Revolving Credit Facility [Member] | Leverage Ratio Applicable Margin [Member] | Minimum [Member]
Debt instrument, participation fee, percent		2.00%
New Credit Agreement [Member] | Revolving Credit Facility [Member] | Leverage Ratio Applicable Margin [Member] | Maximum [Member]
Debt instrument, participation fee, percent		3.50%
Senior Notes [Member]
Long-term debt balance							$ 495,184
Senior Notes [Member] | The 2028 Senior Notes [Member]
Debt instrument, interest rate, stated percentage					7.25%		7.25%							7.25%
Debt instrument, face amount														$ 475,000
Underwriting discount on senior notes														1.16%
Debt instrument, unamortized discount														$ 5,500
Debt instrument total payment					$ 216,000
Debt instrument call premium					3,800
Interest expense debt					200
Loss on Extinguishment					4,900
Debt instrument, redemption price, percentage						103.625%		105.438%
Debt instrument, redemption price, percentage, net of cash proceeds of equity offerings										35.00%
Partially redeemed amount					212,000
Debt instrument, redemption price, percentage, including accrued and unpaid interest										101.00%
Long-term debt balance					261,947		$ 472,184
Payments of debt issuance costs					1,100
Senior Notes [Member] | The 2028 Senior Notes [Member] | Forecast [Member]
Debt instrument, redemption price, percentage	100.00%			101.813%
Senior Notes [Member] | The 2021 Senior Notes [Member]
Proceeds from issuance of long-term debt			$ 469,500
Previously outstanding			6.875%
Interest expense debt					$ 34,600		$ 35,400		34,400
Senior Notes [Member] | IQ Notes [Member]
Debt instrument, interest rate, stated percentage					7.25%		7.25%					6.515%	6.515%
Debt instrument, face amount												$ 36,800	$ 50.0
Payment of Interest					$ 1,100
Interest expense debt					1,100		$ 2,200		$ 2,300
Debt instrument, unamortized premium, percentage of principal												103.65%	103.65%
Debt instrument, unamortized premium													$ 1.8
Debt instrument, effective annual yield												5.74%	5.74%
Long-term debt balance							$ 0						$ 48.2
Senior Notes [Member] | New Credit Agreement [Member]
Letters of credit, drawn amount					$ 225,000