Discontinued Operations Balance Sheet and Income Statement (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Assets of Disposal Group, Including Discontinued Operation [Abstract]
Accounts receivable	$ 1,670
Inventories	68
Other property, net	133
Total assets held-for-sale	1,871
Liabilities of Disposal Group, Including Discontinued Operation [Abstract]
Accounts payable	(2,182)
Royalty payable	(1,221)
Other current liabilities	(7)
Total liabilities held-for-sale	(3,410)
Total net held-for-sale properties	(1,539)
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Oil and gas revenues	4,821	18,663
Pretax income (loss) from discontinued operations	(2,078)	3,168
Income tax expense (benefit)	(952)	1,170
Income (Loss) From Discontinued Operations	(1,126)	1,998
Loss on disposal of discontinued operations	(1,667)	0
Income tax benefit	(617)	0
Loss on Disposal of Discontinued Operations	(1,050)	0
Total Income (Loss) From Discontinued Operations	(2,176)	1,998
Diluted Earnings Per Average Common Share
Income (Loss) from Discontinued Operations (in dollars per share)	$ (0.02)	$ 0.03
Loss on Disposal of Discontinued Operations (in dollars per share)	$ (0.01)	$ 0.00
Total Income (Loss) From Discontinued Operations (in dollars per share)	$ (0.03)	$ 0.03
Basic Earnings Per Average Common Share
Income (Loss) from Discontinued Operations (in dollars per share)	$ (0.02)	$ 0.03
Loss on Disposal of Discontinued Operations (in dollars per share)	$ (0.01)	$ 0.00
Total Income (Loss) From Discontinued Operations (in dollars per share)	$ (0.03)	$ 0.03
Black Warrior Basin
Assets of Disposal Group, Including Discontinued Operation [Abstract]
Accounts receivable	0
Inventories	0
Other property, net	0
Total assets held-for-sale	0
Liabilities of Disposal Group, Including Discontinued Operation [Abstract]
Accounts payable	(2,172)
Royalty payable	0
Other current liabilities	0
Total liabilities held-for-sale	(2,172)
Total net held-for-sale properties	(2,172)
North Louisiana/East Texas
Assets of Disposal Group, Including Discontinued Operation [Abstract]
Accounts receivable	1,670
Inventories	68
Other property, net	133
Total assets held-for-sale	1,871
Liabilities of Disposal Group, Including Discontinued Operation [Abstract]
Accounts payable	(10)
Royalty payable	(1,221)
Other current liabilities	(7)
Total liabilities held-for-sale	(1,238)
Total net held-for-sale properties	$ 633