Note 8 - Revenue (Details) T in Millions	3 Months Ended
	Mar. 31, 2024 T $ / T
REVENUES
Term of domestic sales contracts	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
REVENUES
Percentage OF Committed Tons	78.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
REVENUES
Percentage OF Committed Tons	21.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
REVENUES
Percentage OF Committed Tons	1.00%
Contracts with Indexed Based Pricing Mechanisms
REVENUES
Outstanding performance obligation, mass	3.1
Fixed Priced Contracts
REVENUES
Outstanding performance obligation, mass	1.1
Average per ton | $ / T	168