Supplemental Disclosures (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Supplemental Disclosures [Line Items]
Total accrued liabilities	$ 191,233	$ 174,348
Accrued evaluated and unproved and unevaluated property costs
Supplemental Disclosures [Line Items]
Total accrued liabilities	108,200	105,347
Accrued midstream property costs
Supplemental Disclosures [Line Items]
Total accrued liabilities	22,817	14,823
Accrued lease operating expenses
Supplemental Disclosures [Line Items]
Total accrued liabilities	12,234	12,611
Accrued interest on debt
Supplemental Disclosures [Line Items]
Total accrued liabilities	18,228	8,345
Accrued asset retirement obligations
Supplemental Disclosures [Line Items]
Total accrued liabilities	1,274	1,176
Accrued partners’ share of joint interest charges
Supplemental Disclosures [Line Items]
Total accrued liabilities	26,109	27,628
Other
Supplemental Disclosures [Line Items]
Total accrued liabilities	$ 2,371	$ 4,418