Supplemental Information On Oil And Gas Exploration And Production Activities (Unaudited) - Schedule Of Standardized Measure (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Extractive Industries [Abstract]
Future cash inflows	$ 4,479,757	$ 2,948,989
Future production costs	(1,013,131)	(757,716)
Future development costs	(963,536)	(677,093)
Future income tax expense	(90,570)	(33,644)
Future net cash flows	2,412,520	1,480,536
10% annual discount for estimated timing of cash flows	(1,453,068)	(887,836)
Standardized measure of discounted future net cash flows	959,452	592,700	$ 85,883
Standardized measure of discounted future net cash flows attributable to noncontrolling interests	$ 530,200	$ 336,100