Revenue Recognition (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Performance obligations satisfied in prior period, amount recognized	$ 1,400,000	$ 2,100,000
Opening contract liability	800,000	$ 1,000,000
Contract assets recognized	0
Thacker Pass
Disaggregation of Revenue [Line Items]
Reimbursable costs	4,900,000
Advance paid	3,500,000
Cost reimbursement, commercial mining milestone, fee	4,700,000
Thacker Pass | Equipment
Disaggregation of Revenue [Line Items]
Equipment acquired	$ 23,300,000
Minimum
Disaggregation of Revenue [Line Items]
Primary term of contract	3 years
Maximum
Disaggregation of Revenue [Line Items]
Primary term of contract	5 years
Maximum | Thacker Pass
Disaggregation of Revenue [Line Items]
Capital expenditures	$ 50,000,000