FINANCING ARRANGEMENTS - Capital Leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Capital Leases
Total cost of the leased equipment	$ 1,624		$ 1,624		$ 1,524
Current maturities of capital leases	350		350		$ 295	[1]
Interest expense related to the leased assets	19	$ 0	70	$ 0
Depreciation expense related to the leased assets	41	$ 0	122	$ 0
Future minimum lease payments under non-cancelable capital leases
Remainder of 2018	121		121
2019	398		398
2020	398		398
2021	398		398
2022	223		223
Thereafter	2		2
Total noncancelable future lease commitments	1,540		1,540
Less interest	(153)		(153)
Present value obligations under capital leases	$ 1,387		$ 1,387

[1] The balance sheet at December 31, 2017 has been derived from the audited financial statements at that date