BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accounts Receivable and Inventories (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Activity in the allowance for doubtful accounts
Beginning balance	$ 1,192	$ 506
Additional reserves	267	803
Writeoffs	(225)	(107)
Effect of foreign currency translation	6	(10)
Ending balance	1,240	1,192
Inventories
Parts and raw materials	87,381	89,100
Work-in-process	11,456	11,686
Finished goods	18,849	16,322
Inventories	$ 117,686	$ 117,108