XML 59 R37.htm IDEA: XBRL DOCUMENT v3.20.4
Summary of Significant Accounting Policies - Schedule of Percent of Consolidated Revenue of Major Customers, Those Whose Total Represented 10% or More of Oil, Natural Gas and NGL Revenues (Details) - Sales Revenue - Customer Concentration Risk
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Shell Trading (US) Company      
Concentration Risk [Line Items]      
Concentration risk, percentage 47.00% 58.00% 65.00%
Phillips 66      
Concentration Risk [Line Items]      
Concentration risk, percentage 22.00% 28.00% 18.00%
Chevron Products Company      
Concentration Risk [Line Items]      
Concentration risk, percentage 12.00%