TAXES - Unrecognized Tax Benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
TAXES
Liability for uncertain tax positions recorded	$ 0	$ 0	$ 0
Change in uncertain tax positions, increase	0
Change in uncertain tax positions, decrease	0
Interest expense or penalties for uncertain tax positions recorded	$ 0	$ 0	$ 0