Fair Value Disclosure (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	$ 17,696	$ 18,663
Gain (loss) on equity securities	(726)	1,805
Long-term debt	$ 100,838	99,400
Mining contracts settlement period (in days)	60 days
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on equity securities	$ (2,100)	300
Quoted Prices in Active Markets for Identical Assets (Level 1) | Reported Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	4,200	6,300
Equity securities cost			$ 2,000
Quoted Prices in Active Markets for Identical Assets (Level 1) | Bellaire
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on equity securities	1,400	1,500
Quoted Prices in Active Markets for Identical Assets (Level 1) | Bellaire | Reported Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	13,500	12,300
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt fair value	$ 100,100	$ 97,900