Disclosures about Fair Value of Financial Instruments - Schedule of Financial Assets and Liabilities Measured at Fair Value (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Exploration Expense	$ 100,211,000	$ 162,539,000	$ 39,345,000
Assets:
Total assets	127,632,000	211,421,000
Liabilities:
Total liabilities	(158,522,000)	(168,963,000)
Net liability	(30,890,000)	42,458,000
Level 1
Assets:
Total assets	0	0
Liabilities:
Total liabilities	0	0
Net liability	0	0
Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Impairment of oil and gas properties	0	500,000	$ 1,100,000
Assets:
Total assets	127,632,000	211,421,000
Liabilities:
Total liabilities	(158,522,000)	(168,963,000)
Net liability	(30,890,000)	42,458,000
Level 3
Assets:
Total assets	0	0
Liabilities:
Total liabilities	0	0
Net liability	0	0
Commodity derivative instruments(1)
Assets:
Commodity derivative contracts	127,632,000	211,421,000
Liabilities:
Commodity derivative instruments(1)	(158,522,000)	(168,963,000)
Commodity derivative instruments(1) | Level 1
Assets:
Commodity derivative contracts	0	0
Liabilities:
Commodity derivative instruments(1)	0	0
Commodity derivative instruments(1) | Level 2
Assets:
Commodity derivative contracts	127,632,000	211,421,000
Liabilities:
Commodity derivative instruments(1)	(158,522,000)	(168,963,000)
Commodity derivative instruments(1) | Level 3
Assets:
Commodity derivative contracts	0	0
Liabilities:
Commodity derivative instruments(1)	$ 0	$ 0