INCOME TAXES, Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets [Abstract]
State tax credits	$ 1,033	$ 902
Unfunded pension liability	1,139	1,398
Reserves and accruals	2,828	4,335
Deferred tax assets, net operating loss carryforwards	10,524	12,891
Depreciation	917	1,057
Amortization	0	0
Other accruals	4,915	8,278
Total deferred tax assets	21,356	28,861
Deferred tax liabilities [Abstract]
Reserves and accruals	0	64
Depreciation	989	3,028
Amortization	8,490	15,361
Other accruals	946	973
Total deferred tax liabilities	10,425	19,426
Valuation allowance	8,343	7,485
Net deferred tax assets/(liabilities)	$ 2,588	$ 1,950