Supplementary Information on Oil and Gas Producing Activities (Unaudited) - Summary of the Proved Reserves (Detail)	12 Months Ended
	Dec. 31, 2015 bbl Mcf	Dec. 31, 2014 bbl Mcf
Oil [Member]
Reserve Quantities [Line Items]
Beginning of the period	17,374	19,073
Revisions of previous estimates	(10,826)	397
Extensions and discoveries		8
Production	(1,091)	(2,104)
End of period	5,457	17,374
Proved Developed Reserves, End of Year	5,457	17,374
Gas [Member]
Reserve Quantities [Line Items]
Beginning of the period | Mcf	76,933,121	42,536,167
Revisions of previous estimates | Mcf	(30,046,251)	2,579,426
Extensions and discoveries | Mcf	942,402	40,437,710
Production | Mcf	(6,491,172)	(6,273,384)
Purchases of minerals in place | Mcf		(2,346,798)
Sales of minerals in place-leaseholds | Mcf	(3,721,437)
End of period | Mcf	37,616,663	76,933,121
Proved Developed Reserves, End of Year | Mcf	32,129,895	62,489,000
NGL [Member]
Reserve Quantities [Line Items]
Beginning of the period	1,269,207	890,367
Revisions of previous estimates	343,816	124,580
Extensions and discoveries		453,816
Production	(191,446)	(127,530)
Purchases of minerals in place		(72,026)
End of period	1,421,577	1,269,207
Proved Developed Reserves, End of Year	1,421,577	1,269,207