Note 12 - Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Payment of minimum royalties	$ 5.7	$ 4.5	$ 9.0
Ramaco Coal, LLC \| On-Going Administrative Services
Charges to related party		0.1	$ 0.2
Ramaco Coal, LLC \| Accounts Payable and Accrued Liabilities \| Mineral Lease and Surface Rights Agreements
Due to Related Parties, Total	$ 0.4	$ 0.4

Carrying amount as of the balance sheet date of obligations due all related parties.

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+ Details