Additional Balance Sheet Information - Schedule of Additional Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accounts receivable, net
Trade accounts	$ 183,700	$ 362,973
Joint interest accounts	64	101
Other accounts	796	567
Accounts receivable, gross	184,560	363,641
Allowance for doubtful accounts	(1,184)	(1,238)
Accounts receivable, net	183,376	362,403
Other assets
Deferred compensation plan	16,962	14,699
Debt issuance costs	9,971	4,572
Income taxes receivable	0	8,165
Operating lease right-of-use assets	39,690	0
Other accounts	63	61
Other assets	66,686	27,497
Accounts payable
Trade accounts	35,178	30,033
Natural gas purchases	8,487	0
Royalty and other owners	32,597	61,507
Accrued transportation	49,373	50,540
Accrued capital costs	46,376	43,207
Taxes other than income	8,691	19,824
Income taxes payable	0	1,134
Other accounts	4,258	35,694
Accounts payable	184,960	241,939
Accrued liabilities
Employee benefits	17,873	21,761
Taxes other than income	3,664	1,472
Operating lease liabilities	5,782	0
Asset retirement obligations	1,000	1,000
Other accounts	865	994
Accrued liabilities	29,184	25,227
Other liabilities
Deferred compensation plan	28,345	25,780
Operating lease liabilities	33,797	0
Other accounts	8,809	34,391
Other liabilities	$ 70,951	$ 60,171