Components of Selected Balance Sheet Accounts (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Other current assets:
Tubular inventory and well materials	$ 2,214	$ 2,878
Prepaid expenses	2,718	4,184
Other Assets, Miscellaneous, Current	7	42
Other Assets, Current	4,939	7,104
Other assets:
Assets of supplemental employee retirement plan (“SERP”)	4,220	4,123
Deferred issuance costs of the Revolver	0	1,572
Other	2,520	2,655
Other assets	6,740	8,350
Accounts payable and accrued liabilities:
Trade accounts payable 2	23,394	11,603
Drilling costs	2,228	12,074
Royalties and revenue – related	10,662	39,119
Compensation – related 2	685	9,904
Interest 2	18	15,531
Other 2	16,173	15,294
Accounts payable and accrued liabilities	53,160	103,525
Other liabilities:
Deferred gains on sale of assets	80,967	82,943
Firm transportation obligation 2	0	10,705
Asset retirement obligations (“AROs”)	3,379	2,621
Defined benefit pension obligations 2	0	1,129
Postretirement health care benefit obligations 2	0	731
Compensation-related	0	1,447
Deferred compensation – SERP obligations and other 2	0	4,434
Other 2	0	928
Other liabilities	$ 84,346	$ 104,938