XML 107 R119.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Supplemental Information on Natural Gas and Oil Exploration, Development and Production Activities (Unaudited) - Standardized Measure of Discounted Future Net Cash Flows (Detail) - USD ($)
$ in Thousands
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Extractive Industries [Abstract]        
Future cash inflows $ 48,718,733 $ 64,287,737    
Future costs:        
Production (23,320,477) (25,626,373)    
Development [1] (3,219,349) (3,824,936)    
Future net cash flows before income taxes 22,178,907 34,836,428    
Future income tax expense (4,179,297) (7,285,274)    
Total future net cash flows before 10% discount 17,999,610 27,551,154    
10% annual discount (11,371,037) (16,435,560)    
Standardized measure of discounted future net cash flows $ 6,628,573 $ 11,115,594 $ 7,165,214 $ 3,451,929
[1] 2019 includes $339.1 million of undiscounted future asset retirement costs estimated as of December 31, 2019, using current estimates of future abandonment costs.