BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accounts Receivable and Inventories (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Activity in the allowance for doubtful accounts
Beginning balance	$ 367	$ 802	$ 177
Allowance for doubtful accounts acquired			460
Additional reserves	333	473	158
Write-offs	(117)	(882)
Recoveries			1
Effect of foreign currency translation	28	(26)	6
Ending balance	611	367	802
Inventories
Parts and raw materials	23,710	21,573
Work-in-process	2,404	2,924
Finished goods	3,730	4,403
Inventory, gross	29,844	28,900
Less reserves	(3,669)	(3,529)
Inventories, net	26,175	25,371
Provision for excess and obsolete inventory	$ 432	$ 753	$ 105