Supplemental Oil and Gas Disclosures (Unaudited) (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Costs Incurred in Acquisition, Exploration, and Development Activities Detail [Table]
Acquisition	$ 0	$ 141	$ 5,497
Exploration	0	0	16,822
Development	0	5,798	87,465
Total costs incurred	0	5,939	109,784
Results of Operations for Producing Activities Detail [Table]
Oil and gas sales revenues	6,158	81,941	197,841
Production (lifting) costs	3,749	33,496	71,066
Depreciation, depletion, and amortization	60	27,640	73,679
Impairments of properties	0	15,233	63,774
Excess decommissioning and abandonment costs	40,767	78,382	53,997
Exploration expenses	0	77	306
Accretion expense	979	3,705	5,008
Dry hole costs	0	(32)	325
Gain on insurance recoveries	0	0	(2,541)
Pretax income (loss) from producing activities	(39,397)	(76,560)	(67,773)
Income tax expense (benefit)	(13,789)	(26,797)	(25,186)
Results of oil and gas producing activities	$ (25,608)	$ (49,763)	$ (42,587)
Aggregate percentage of sold reserves		95.00%