Supplemental Oil and Gas Disclosures (Unaudited) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Results of Operations for Producing Activities Detail [Table]
Oil and gas sales revenues	$ 751	$ 2,438	$ 4,722
Production (lifting) costs	643	921	2,002
Depreciation, depletion, and amortization	0	0	30
Excess decommissioning and abandonment costs	2,593	2,665	73,194
Accretion expense	1,362	1,375	130
Gain on insurance recoveries	0	0	(6)
Pretax income (loss) from producing activities	(3,847)	(2,523)	(70,628)
Income tax expense (benefit)	0	0	0
Results of oil and gas producing activities	$ (3,847)	$ (2,523)	$ (70,628)