Nature of operations and summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Components of accounts receivable

Accounts receivable consisted of the following:

	December 31, 2018			December 31, 2017
Joint interests	$	31,573		$	29,032
Accrued commodity sales	30,287			26,516
Derivative settlements	2,092			157
Other	3,375			5,326
Allowance for doubtful accounts	(1,240		)	(668		)
	$	66,087		$	60,363

Components of inventory

Inventories consisted of the following:

	December 31, 2018			December 31, 2017
Equipment inventory	$	3,663		$	4,163
Commodities	574			1,154
Inventory valuation allowance	(178		)	(179		)
	$	4,059		$	5,138

Adjustments to inventory

	Successor				Predecessor
	Period from		Period from		Period from		Period from
	January 1, 2018		March 22, 2017		January 1, 2017		January 1, 2016
	through		through		through		through
	December 31, 2018		December 31, 2017		March 21, 2017		December 31, 2016
Inventory - valuation adjustment	$	—	$	179	$	—	$	1,393

Adjustments to oil and natural gas properties

We recorded adjustments to the oil and natural gas properties, for the periods disclosed below. The loss is reflected in “Loss on impairment of oil and gas assets” in our consolidated statements of operations.

	Successor				Predecessor
	Period from		Period from		Period from		Period from
	January 1, 2018		March 22, 2017		January 1, 2017		January 1, 2016
	through		through		through		through
	December 31, 2018		December 31, 2017		March 21, 2017		December 31, 2016
Ceiling test impairment	$	20,065	$	42,146	$	—	$	281,079

Components of other expense

Other expense consisted of the following:

	Successor
	Period from		Period from
	January 1, 2018		March 22, 2017
	through		through
	December 31, 2018		December 31, 2017
Restructuring	$	425	$	3,531
Subleases	1,611		197
Total other expense	$	2,036	$	3,728

Components of cost reduction initiatives expense

The expense consists of costs for one-time severance and termination benefits in connection with our reductions in force and third party legal and professional services we have engaged to assist in our cost savings initiatives as follows:

	Successor				Predecessor
	Period from		Period from		Period from		Period from
	January 1, 2018		March 22, 2017		January 1, 2017		January 1, 2016
	through		through		through		through
	December 31, 2018		December 31, 2017		March 21, 2017		December 31, 2016
One-time severance and termination benefits	$	1,034	$	678	$	608	$	2,772
Professional fees	—		13		21		107
Total cost reduction initiatives expense	$	1,034	$	691	$	629	$	2,879