Supplemental Information On Oil And Gas Exploration And Production Activities (Unaudited) - Narrative (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) MMBTU MBoe $ / bbl $ / MMBTU	Dec. 31, 2018 USD ($) MBoe $ / bbl $ / MMBTU	Dec. 31, 2017 MBoe
Reserve Quantities [Line Items]
Additions to oil and gas properties | $	$ 210,907	$ 226,628
Natural gas liquids prices used to value reserves | $ / bbl	16.17	28.81
Proved extensions and discoveries	5,065	16,209
Sales of minerals in place	(32)	(6,596)
Sales of minerals in place		(4,702)
Purchases of minerals in place		6,810
Revision to previous estimates	(4,642)	6,075
Revisions	(3,362)	5,838
Improved proved developed reserves		300
Proved undeveloped reserve attributable to noncontrolling interests BOE	34,243	41,560	34,029
Conversion period of proved undeveloped reserves into proved developed producing reserves		5 years
Estimated capital expenditures of proved undeveloped reserves | $	$ 103,800	$ 41,500
Estimated proved undeveloped reserves, conversions to developed, gross	30,000	14,000
Estimated proved undeveloped reserves, conversions to developed, net	12,300	6,200
Estimated conversion of proved undeveloped reserves into proved developed producing reserves	9,900	4,300
Capital expenditures of proved undeveloped reserves | $	$ 111,500	$ 55,400
Modified proved undeveloped reserves, conversions to developed, gross	32,000	11,000
Modified proved undeveloped reserves, conversions to developed, net	13,400	6,800
Modified conversion of proved undeveloped reserves into proved developed producing reserves	10,300	4,400
Extensions and discoveries	1,230	13,734
Oil prices used to value reserves (in dollars per barrel) | $ / bbl	52.60
Natural gas prices used to value reserves (in dollars per MMBtu) | $ / MMBTU	0.91
Natural gas liquids prices used to value reserves (in dollars per barrel) | $ / bbl	16.17
Non-Cancelable Agreement
Reserve Quantities [Line Items]
Holding pipeline capacity | MMBTU	10,000
Midland Basin
Reserve Quantities [Line Items]
Proved extensions and discoveries	5,100
Sales of minerals in place		0
Sales of minerals in place		4,700
Purchases of minerals in place		4.7
Extensions and discoveries		13,700
Proved undeveloped reserves sales of minerals in place, disposed of during period		3.7
Eagle Ford
Reserve Quantities [Line Items]
Sales of minerals in place		0
Sales of minerals in place		1.0
Williston Basin
Reserve Quantities [Line Items]
Sales of minerals in place	(32.0)	(6,600)
Henry Hub Spot Price
Reserve Quantities [Line Items]
Unweighted average of first of the month prices of natural gas | $ / MMBTU	2.58	3.10
West Texas Intermediate Spot Price
Reserve Quantities [Line Items]
Unweighted average of first of the month prices of oil | $ / bbl	55.69	65.56
New Wells
Reserve Quantities [Line Items]
Additions to oil and gas properties | $	$ 100	$ 300
Operated Eagle Ford and Non-operated Bakken Properties
Reserve Quantities [Line Items]
Proved extensions and discoveries		16,200
Non-operated Midland Basin Properties | Lynden Arrangement
Reserve Quantities [Line Items]
Purchases of minerals in place		6,800