v3.3.1.900
Disclosures About Oil and Gas Producing Activities - Summary of Changes in Quantities of Proved Oil, NGL and Natural Gas Reserves (Parenthetical) (Detail)
 12 Months Ended
Dec. 31, 2015
MBoe
MBbls
MMcf
Dec. 31, 2014
MBoe
MBbls
MMcf
Dec. 31, 2013
MBoe
MBbls
MMcf
Reserve Quantities [Line Items]      
Beginning Balance, Proved Developed Reserves, MBoe | MBoe 60,220 45,189 32,774
Ending Balance, Proved Developed Reserves, MBoe | MBoe 61,856 60,220 45,189
Beginning Balance, Proved Undeveloped Reserves, MBoe | MBoe 86,028 69,472 62,705
Ending Balance, Proved undeveloped Reserves, MBoe | MBoe 104,790 86,028 69,472
Field fuel | MMcf 1,530 1,390 560
Natural Gas (MMcf) [Member]      
Reserve Quantities [Line Items]      
Beginning Balance, Proved Developed Reserve, MMcf | MMcf 138,961 99,742 73,178
Ending Balance, Proved Developed Reserve, MMcf | MMcf 154,652 138,961 99,742
Beginning Balance, Proved Undeveloped Reserves, MMcf | MMcf 161,059 116,260 101,582
Ending Balance, Proved Undeveloped Reserves, MMcf | MMcf 221,335 161,059 116,260
Field fuel | MMcf 13,262 10,773 6,737
NGLs (MBbls) [Member]      
Reserve Quantities [Line Items]      
Beginning Balance, Proved Developed Reserves, MBbls 19,082 14,919 11,761
Ending Balance, Proved Developed Reserves, MBbls 20,414 19,082 14,919
Beginning Balance, Proved Undeveloped Reserves, MBbls 21,825 17,674 17,339
Ending Balance, Proved Undeveloped Reserves, MBbls 29,072 21,825 17,674
Field fuel 1,694 1,461 951
Oil (MBbls) [Member]      
Reserve Quantities [Line Items]      
Beginning Balance, Proved Developed Oil Reserves, MBbls 17,978 13,646 8,816
Ending Balance, Proved Developed Oil Reserves, MBbls 15,667 17,978 13,646
Beginning Balance, Proved Undeveloped Oil Reserves, MBbls 37,360 32,421 28,436
Ending Balance, Proved Undeveloped Oil Reserves, MBbls 38,829 37,360 32,421
Field fuel 1,882 2,024 1,444