Components of Selected Balance Sheet Accounts (Detail) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Other current assets:
Tubular inventory and well materials		$ 5,146	$ 2,125
Prepaid expenses		1,104	903
Other		0	0
Other current assets		6,250	3,028
Other assets:
Deferred issuance costs of the Credit Facility		2,857	2,785
Escrow Deposit Remaining	[1]	3,210	0
Other		2,440	2,544
Accounts payable and accrued liabilities:
Trade accounts payable		22,579	9,825
Drilling costs		22,389	2,479
Royalties and revenue - related		39,287	26,116
Compensation-related		2,975	2,557
Interest		223	55
Bankruptcy Claims, amount reserved for outstanding claims		3,933	3,922
Other		4,795	4,743
Other liabilities:
Asset retirement obligations		3,286	2,459
Defined benefit pension obligations		971	1,025
Postretirement health care benefit obligations		476	488
Other		$ 100	$ 100

[1] 1 Represents amount remaining in the Escrow Account for the Devon Acquisition which will fully fund the remaining liability due to Devon for the final settlement (see Note 5).