Amount of cash inflow for proceeds from settlement of insurance claim, classified as investing activities. Excludes insurance settlement classified as operating activities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 21B
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-21B

Name:	us-gaap_ProceedsFromInsuranceSettlementInvestingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Note 3 - Property, Plant and Equipment - Narrative (Details) $ in Millions		12 Months Ended
	Jul. 10, 2022 employee	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2024 USD ($)
Property, plant, and equipment
Idle mine costs			$ 9.5
Proceeds from insurance for methane ignition on mine		$ 9.2
Accrued loss recovery asset				$ 3.9
Mining property and mineral rights
Property, plant, and equipment
Number of personnel in the mine \| employee	0
Gain on Insurance Recovery		$ 8.1
Accrued loss recovery asset			$ 1.1