Note 12 - Self Insurance (Details Textual) $ in Thousands |
Dec. 31, 2021
USD ($)
item
|
Dec. 31, 2020
USD ($)
|
|---|---|---|
| Restricted Cash and Cash Equivalents, Total | $ 3,283 | $ 4,030 |
| Future Workers' Compensation Claim Payments [Member] | ||
| Restricted Cash and Cash Equivalents, Total | $ 3,300 | 4,000 |
| Mining Properties and Mineral Rights [Member] | ||
| Number of Mining Units | 7 | |
| Area of Real Estate Property | item | 10 | |
| Operating Lease, Liability, Total | $ 260,000 | $ 269,000 |
| X | ||||||||||
- Definition Total active underground mining miles with equipment that is self-insured. No definition available.
|
| X | ||||||||||
- Definition The number of mining units. No definition available.
|
| X | ||||||||||
- Definition Present value of lessee's discounted obligation for lease payments from operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|