Components of Selected Balance Sheet Accounts (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other current assets:
Tubular inventory and well materials	$ 3,474	$ 4,061
Prepaid expenses	1,079	1,064
Other Assets, Current	4,553	5,125
Other assets:
Deferred issuance costs of the Revolver	2,060	2,437
Operating Lease, Right-of-Use Asset	2,451	0
Other	44	44
Other assets	4,555	2,481
Accounts payable and accrued liabilities:
Trade accounts payable	23,020	16,507
Drilling costs	36,003	22,434
Royalties and revenue – related	46,521	51,212
Production, ad valorem and other taxes	3,747	2,418
Compensation – related	2,091	4,489
Interest	815	670
Operating Lease, Liability, Current	689	0
Other	4,382	5,970
Accounts payable and accrued liabilities	117,268	103,700
Other liabilities:
Asset retirement obligations	4,370	4,314
Operating Lease, Liability, Noncurrent	2,109	0
Defined benefit pension obligations	828	857
Postretirement health care benefit obligations	377	362
Other liabilities	$ 7,684	$ 5,533