XML 74 R60.htm IDEA: XBRL DOCUMENT v3.21.1
Supplemental Oil And Gas Information (Schedule Of Net Proved Oil And Gas Reserves And The Changes In Net Proved Oil And Gas Reserves) (Details)
12 Months Ended
Dec. 31, 2020
MBoe
MMcf
MBbls
Dec. 31, 2019
MBoe
MMcf
MBbls
Dec. 31, 2018
MBoe
MMcf
MBbls
Reserve Quantities [Line Items]      
Proved reserves 803 1,094  
Revisions of previous estimates (200) (203)  
Improved recovery  
Purchase of reserves in place  
Extensions and discoveries 8  
Production (86) (94)  
Sales of reserves in place (2)  
Proved reserves 517 803 1,094
Proved developed reserves (equivalent) | MBoe 517 803 976
Proved undeveloped reserves (equivalent) | MBoe 118
Oil [Member]      
Reserve Quantities [Line Items]      
Proved reserves 803 1,094  
Revisions of previous estimates (200) (203)  
Improved recovery  
Purchase of reserves in place  
Extensions and discoveries 8  
Production (86) (94)  
Sales of reserves in place (2)  
Proved reserves 517 803 1,094
Proved developed reserves (volume) 517 803 976
Proved undeveloped reserves (volume) 118
Gas [Member]      
Reserve Quantities [Line Items]      
Proved reserves | MMcf  
Revisions of previous estimates | MMcf  
Improved recovery | MMcf  
Purchase of reserves in place | MMcf  
Extensions and discoveries | MMcf  
Production | MMcf  
Sales of reserves in place | MMcf  
Proved reserves | MMcf
Proved developed reserves (volume) | MMcf
Proved undeveloped reserves (volume) | MMcf