INCOME TAXES - Tax Effect of Significant Items Comprising Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax asset:
Net operating loss carryforward	$ 18,236	$ 21,652
Property, plant and equipment - refinery	23,447	22,333
Other	3,016	2,879
Total deferred tax asset	44,699	46,864
Deferred tax liability:
Property, plant and equipment - terminals	1,189	2,124
Other	0	55
Total deferred tax liability	1,189	2,179
Net deferred tax asset	43,510	44,685
Less: Valuation allowance	(41,056)	(42,893)
Deferred taxes, net	$ 2,454	$ 1,792