Supplemental Disclosures of Cash Flow Information - Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental Cash Flow Information [Abstract]
Cash paid for interest	$ 50,063	$ 61,295	$ 58,193
Cash paid for income taxes	0	0	0
Supplemental disclosures of non-cash investing and financing activities:
Accrued liabilities - oil and gas properties	98,346	43,980	23,944
Change in asset retirement obligations, net of disposals	10,778	5,376	(4,799)
Fair value of debt exchanged for common stock	0	48,992	74,400
Retirement of treasury stock	(1,535)	(1,253)	(1,114)
Properties exchanged in non-cash transactions	0	13,323	0
Issuance of common stock for Merger	$ 484,000	$ 0	$ 0