Derivative financial instruments (Details 2) - Oil Swaps [Member] - 2020 [Member]	Dec. 31, 2020 USD ($) $ / shares
First quarter [Member]
Volume (Bbl) | $	$ 15,255
Price per Bbl | $ / shares	$ 49.40
Second quarter [Member]
Volume (Bbl) | $	$ 15,180
Price per Bbl | $ / shares	$ 50.87
Third quarter [Member]
Volume (Bbl) | $	$ 5,200
Price per Bbl | $ / shares	$ 38.25
Fourth quarter [Member]
Volume (Bbl) | $	$ 0
Price per Bbl | $ / shares	$ 0.0