Additional Balance Sheet Information - Schedule of Additional Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accounts receivable, net
Trade accounts	$ 97,205	$ 116,772
Joint interest accounts	2,215	2,013
Other accounts	2,484	2,557
Receivables Gross Current	101,904	121,342
Allowance for doubtful accounts	(1,033)	(1,113)
Accounts receivable, net	100,871	120,229
Inventories
Tubular goods and well equipment	14,186	14,655
Natural gas in storage	1,762	2,364
Other accounts	0	30
Inventories	15,948	17,049
Other assets
Deferred compensation plan	13,013	12,921
Debt issuance costs	13,957	14,871
Other accounts	59	64
Other assets	27,029	27,856
Accounts payable
Trade accounts	28,942	30,038
Natural gas purchases	1,101	2,231
Royalty and other owners	69,776	75,106
Accrued capital costs	26,930	27,479
Taxes other than income	16,904	14,628
Other accounts	4,341	10,925
Accounts payable current	147,994	160,407
Accrued liabilities
Employee benefits	8,725	13,870
Taxes other than income	6,104	5,073
Income taxes payable	97	0
Other accounts	2,900	5,980
Accrued liabilities	17,826	24,923
Other liabilities
Deferred compensation plan	25,144	22,371
Other accounts	3,596	3,653
Other liabilities	$ 28,740	$ 26,024