Discontinued Operations Discontinued Operations (Statements of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues	$ 0	$ 0
General and administrative	437	5
Accretion related to asset retirement obligations	0	36
Gain on sale of discontinued operations	0	(37,294)
Increase in estimated future obligations	535	0
Loss on derivative instruments, net	20	44
Other income, net	0	(24)
Income (Loss) From Discontinued Operations Before Income Taxes	(992)	37,233
Income tax (expense) benefit	347	(13,575)
Income (Loss) From Discontinued Operations, Net of Income Taxes	$ (645)	$ 23,658