XML 134 R114.htm IDEA: XBRL DOCUMENT v3.20.4
Supplemental Information on Natural Gas and Oil Exploration, Development and Production Activities (Unaudited) - Costs Incurred for Property Acquisition, Exploration and Development (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Acquisitions      
Acreage purchases [1] $ 26,166 $ 57,324 $ 62,390
Oil and gas properties [1] 0 0 1,683
Development [1] 369,093 666,984 834,552
Exploration:      
Exploration drilling costs incurred [1] 7,709 0 1,380
Gas gathering facilities:      
Development [1] 3,694 3,583 10,218
Subtotal [1] 439,317 764,574 944,340
Asset retirement obligations [1] 2,610 11,193 28,826
Total costs incurred [1] 441,927 775,767 973,166
Expense      
Exploration:      
Exploration costs incurred [1] 31,376 35,117 32,196
Stock-based compensation expense [1] $ 1,279 $ 1,566 $ 1,921
[1] Includes cost incurred whether capitalized or expensed.