Additional Balance Sheet Information - Schedule of Additional Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts receivable, net
Trade accounts	$ 118,840	$ 116,772
Joint interest accounts	1,618	2,013
Other accounts	1,986	2,557
Accounts receivable, net	122,444	121,342
Allowance for doubtful accounts	(1,143)	(1,113)
Accounts receivable, net	121,301	120,229
Inventories
Tubular goods and well equipment	10,962	14,685
Natural gas in storage	2,525	2,364
Inventories	13,487	17,049
Other assets
Deferred compensation plan	12,297	12,921
Debt issuance costs	12,258	14,871
Derivative instruments	1,144	0
Other accounts	78	64
Other assets	25,777	27,856
Other current assets
Prepaid balances and other	3,588	2,671
Derivative instruments	518	0
Other current assets	4,106	2,671
Accounts payable
Trade accounts	26,439	30,038
Natural gas purchases	2,815	2,231
Royalty and other owners	70,631	75,106
Accrued capital costs	44,551	27,479
Taxes other than income	10,349	14,628
Other accounts	5,357	10,925
Accounts payable current	160,142	160,407
Accrued liabilities
Employee benefits	8,040	13,870
Taxes other than income	5,910	5,073
Asset retirement obligations	2,000	2,000
Other accounts	2,249	3,980
Accrued liabilities	18,199	24,923
Other liabilities
Deferred compensation plan	25,088	22,371
Other accounts	4,330	3,653
Other liabilities	$ 29,418	$ 26,024