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Significant Customers and Other Concentrations - Narrative (Details)
12 Months Ended
Dec. 31, 2019
counterparty
Customer
Dec. 31, 2018
Customer
Dec. 31, 2017
Customer
Concentration Risk [Line Items]      
Counterparties With Hedges In Place Number | counterparty 9    
Sales Revenue, Product Line [Member] | Customer Concentration Risk [Member]      
Concentration Risk [Line Items]      
Customers account for production revenues | Customer 3 4 3