Divestitures and acquisitions (Tables)

12 Months Ended

Dec. 31, 2017

Business Combinations [Abstract]

Final estimate of the fair values of the assets acquired and liabilities assumed

The following table reflects an aggregate of the final estimate of the fair values of the assets and liabilities acquired during the year ended December 31, 2016:

(in thousands)	Fair value of acquisitions
Fair value of net assets:
Evaluated oil and natural gas properties	$	4,800
Unevaluated oil and natural gas properties	119,923
Asset retirement cost	1,105
Total assets acquired	125,828
Asset retirement obligations	(1,105		)
Net assets acquired	$	124,723
Fair value of consideration paid for net assets:
Cash consideration	$	124,723

Revenues and expenses of the oil and natural gas properties sold

The following table presents revenues and expenses of the oil and natural gas properties sold included in the accompanying consolidated statements of operations for the year ended December 31:

(in thousands)	2015
Oil, NGL and natural gas sales	$	5,138
Expenses(1)	$	5,791

_____________________________________________________________________________

(1) Expenses include (i) lease operating expense, (ii) production and ad valorem tax expense, (iii) accretion expense and (iv) depletion expense.