FINANCING ARRANGEMENTS - Capital Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
Capital Leases
Total cost of the leased equipment	$ 1,607		$ 1,607			$ 1,524
Current maturities of capital leases	346		346			$ 295	[1]
Interest expense related to the leased assets	26	$ 0	52	$ 0
Depreciation expense related to the leased assets	41	$ 0	81	$ 0
Future minimum lease payments under non-cancelable capital leases
Remainder of 2018	180		180
2019	337		337
2020	356		356
2021	376		376
2022	218		218
Thereafter	1		1
Total noncancelable future lease commitments	1,468		1,468
Less: interest	173		173
Present value obligations under capital leases	$ 1,641		$ 1,641
Forecast
Future minimum lease payments under non-cancelable capital leases
Total noncancelable future lease commitments					$ 17

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