DERIVATIVE FINANCIAL INSTRUMENTS (Details Textual)	Dec. 31, 2018 $ / Rate	Dec. 31, 2017 $ / Rate	Oct. 31, 2017	Sep. 30, 2017
Number Of Barrels Per Day				1,000
Addititional Derivative Contracts [Member]
Number Of Barrels Per Day			1,000
Call Option [Member]
Derivative, Price Risk Option Strike Price		55.35
Call Option [Member] | Scenario, Forecast [Member]
Derivative, Price Risk Option Strike Price	54.60
Call Option [Member] | Addititional Derivative Contracts [Member] | Scenario, Forecast [Member]
Derivative, Price Risk Option Strike Price	54.80
Put Option [Member]
Derivative, Price Risk Option Strike Price		49.00
Put Option [Member] | Scenario, Forecast [Member]
Derivative, Price Risk Option Strike Price	49.00
Put Option [Member] | Addititional Derivative Contracts [Member] | Scenario, Forecast [Member]
Derivative, Price Risk Option Strike Price	51.00