INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2011
INTANGIBLE ASSETS:
Amortization of intangible asset		$ 3,662	$ 7,324	$ 7,324
Remaining intangible asset			3,662
Purchase Power Agreement
INTANGIBLE ASSETS:
Amortization of intangible asset	$ 3,700		$ 7,300	$ 7,300
TCP | Purchase Power Agreement
INTANGIBLE ASSETS:
Intangible asset					$ 55,500