Revolving Credit Facility (Details) - USD ($) $ in Thousands			12 Months Ended
	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2020	Feb. 04, 2021	Dec. 31, 2019
Line of Credit Facility [Line Items]
Revolving credit facility	$ 93,000		$ 93,000		$ 122,500
Debt Instrument, Covenant Description			(a) total funded debt, as defined in the Credit Agreement, to 12-month trailing adjusted EBITDAX ratio cannot be greater than 4.00 to 1.00 on the last day of each fiscal quarter; and (b) adjusted current ratio, as defined in the Credit Agreement, cannot be less than 1.00 to 1.00 as of the last day of any fiscal quarter.
Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, maximum loan amount	2,500,000		$ 2,500,000
Line of credit agreement, current borrowing base	1,100,000		1,100,000
Line of credit agreement, aggregate lender commitment amount	$ 1,100,000		1,100,000		1,200,000
Line of Credit Facility, Dividend Restrictions	12.0 million	50.0 million
Revolving credit facility	$ 93,000		93,000		122,500
Letters of credit	42,000		42,000		0
Available borrowing capacity	965,000		965,000		1,077,500
Credit facility, unamortized deferred financing costs	$ 4,300		$ 4,300		$ 5,900
Line of Credit [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, aggregate lender commitment amount				$ 1,100,000
Revolving credit facility				121,500
Letters of credit				42,000
Available borrowing capacity				$ 936,500
Line of Credit [Member] | Borrowing Base Utilization of 25 Percent [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, unused capacity, commitment fee rate	0.375%
Line of Credit [Member] | Borrowing Base Utilization of 25 Percent [Member] | Eurodollar [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, basis spread on variable rate	1.75%
Line of Credit [Member] | Borrowing Base Utilization of 25 Percent [Member] | Debt Instrument Variable Rate, Alternative Base Rate, And Swingline Loans [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, basis spread on variable rate	0.75%
Line of Credit [Member] | Borrowing Base Utilization Of 25 Percent Or More But Less Than 50 Percent [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, unused capacity, commitment fee rate	0.375%
Line of Credit [Member] | Borrowing Base Utilization Of 25 Percent Or More But Less Than 50 Percent [Member] | Eurodollar [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, basis spread on variable rate	2.00%
Line of Credit [Member] | Borrowing Base Utilization Of 25 Percent Or More But Less Than 50 Percent [Member] | Debt Instrument Variable Rate, Alternative Base Rate, And Swingline Loans [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, basis spread on variable rate	1.00%
Line of Credit [Member] | Borrowing Base Utilization Of 50 Percent Or More But Less Than 75 Percent [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, unused capacity, commitment fee rate	0.50%
Line of Credit [Member] | Borrowing Base Utilization Of 50 Percent Or More But Less Than 75 Percent [Member] | Eurodollar [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, basis spread on variable rate	2.50%
Line of Credit [Member] | Borrowing Base Utilization Of 50 Percent Or More But Less Than 75 Percent [Member] | Debt Instrument Variable Rate, Alternative Base Rate, And Swingline Loans [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, basis spread on variable rate	1.50%
Line of Credit [Member] | Borrowing Base Utilization Of 75 Percent Or More But Less Than 90 Percent [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, unused capacity, commitment fee rate	0.50%
Line of Credit [Member] | Borrowing Base Utilization Of 75 Percent Or More But Less Than 90 Percent [Member] | Eurodollar [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, basis spread on variable rate	2.75%
Line of Credit [Member] | Borrowing Base Utilization Of 75 Percent Or More But Less Than 90 Percent [Member] | Debt Instrument Variable Rate, Alternative Base Rate, And Swingline Loans [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, basis spread on variable rate	1.75%
Line of Credit [Member] | Borrowing Base Utilization Of 90 Percent Or More [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, unused capacity, commitment fee rate	0.50%
Line of Credit [Member] | Borrowing Base Utilization Of 90 Percent Or More [Member] | Eurodollar [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, basis spread on variable rate	3.00%
Line of Credit [Member] | Borrowing Base Utilization Of 90 Percent Or More [Member] | Debt Instrument Variable Rate, Alternative Base Rate, And Swingline Loans [Member]
Line of Credit Facility [Line Items]
Line of credit agreement, basis spread on variable rate	2.00%