Supplemental Information On Oil And Gas Exploration And Production Activities (Unaudited) - Changes in Quantities of Proved Oil and natural Gas Reserves (Details)	12 Months Ended
	Dec. 31, 2019 MBoe MBbls MMcf	Dec. 31, 2018 MBoe MBbls MMcf	Dec. 31, 2017 MBoe MBbls MMcf
Reserve Quantities [Line Items]
Beginning balance | MBoe	98,847	79,976
Extensions and discoveries | MBoe	5,065	16,209
Sales of minerals in place | MBoe	(32)	(6,596)
Purchases of minerals in place | MBoe		6,810
Production | MBoe	(4,902)	(3,627)
Revision to previous estimates | MBoe	(4,642)	6,075
Ending Balance | MBoe	94,336	98,847
Proved developed reserves | MBoe	31,521	23,646	19,961
Proved undeveloped reserves | MBoe	62,815	75,201	60,015
Oil (MBbl)
Reserve Quantities [Line Items]
Beginning balance	59,034	47,327
Extensions and discoveries	3,598	10,148
Sales of minerals in place	(31)	(2,651)
Purchases of minerals in place		3,532
Production	(3,086)	(2,370)
Revision to previous estimates	(6,865)	3,048
Ending balance	52,650	59,034
Proved developed reserves	18,220	14,325	11,949
Proved undeveloped reserves	34,430	44,709	35,378
Natural Gas (MMcf)
Reserve Quantities [Line Items]
Beginning balance | MMcf	113,217	91,088
Extensions and discoveries | MMcf	4,476	17,673
Sales of minerals in place | MMcf	(4)	(14,300)
Purchases of minerals in place | MMcf		9,890
Production | MMcf	(4,760)	(3,610)
Revision to previous estimates | MMcf	(4,939)	12,476
Ending Balance | MMcf	107,990	113,217
Proved developed reserves | MMcf	35,120	26,110	23,336
Proved undeveloped reserves | MMcf	72,870	87,107	67,752
NGLs (MBbl)
Reserve Quantities [Line Items]
Beginning balance	20,943	17,468
Extensions and discoveries	721	3,116
Sales of minerals in place	(1)	(1,562)
Purchases of minerals in place		1,629
Production	(1,022)	(655)
Revision to previous estimates	3,047	947
Ending balance	23,688	20,943
Proved developed reserves	7,447	4,969	4,123
Proved undeveloped reserves	16,241	15,974	13,345