Subsequent events (Tables)

3 Months Ended

Mar. 31, 2017

Subsequent Events [Abstract]

New commodity derivative contracts

After March 31,2017, the Company entered into the following oil price swaps and oil basis swaps to hedge additional amounts of the Company’s estimated future production:

				First		Second		Third		Fourth
				Quarter		Quarter		Quarter		Quarter		Total
Oil Swaps: (a)
	2017:
		Volume (Bbl)				971,000		1,068,000		855,000		2,894,000
		Price per Bbl			$	50.41	$	50.50	$	50.59	$	50.49
Oil Basis Swaps: (b)
	2019:
		Volume (Bbl)		630,000		637,000		644,000		644,000		2,555,000
		Price per Bbl	$	(1.25)	$	(1.25)	$	(1.25)	$	(1.25)	$	(1.25)
(a)	The index prices for the oil price swaps are based on the NYMEX – WTI monthly average futures price.
(b)	The basis differential price is between Midland – WTI and Cushing – WTI.