Note 14 - Related Party Transactions (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
US Subsidiary Of Elekta Member
Related Party Transaction, Purchases from Related Party	$ 1,906,000	$ 1,103,000
Related Party Transaction, Expenses from Transactions with Related Party	759,000	701,000
Purchase Obligation, Total	6,624,000	8,397,000
Due to Related Parties, Total	$ 1,992,000	$ 1,382,000
GKF Subsidiary [Member]
Noncontrolling Interest, Ownership Percentage by Parent	81.00%
US Subsidiary Of Elekta Member
Noncontrolling Interest, Ownership Percentage by Parent	19.00%

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

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+ Details