Commitments and Contingencies (Details Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 bbl	Dec. 31, 2010	Dec. 31, 2009
Commitments and Contingencies (Textual)
Payments related to lease obligations	$ 446	$ 703	$ 738
Contingent liability to surety insurance company	90,652
Committed to the use of drilling rigs and the acquisition of seismic data, value	59,276
Committed to the use of drilling rigs and the acquisition of seismic data, Period	3 years
Minimum barrels of oil spill to impose financial responsibility under Oil Pollution Act	1,000
Minimum financial responsibility in amounts if oil spill exceeds minimum quantity of barrels of oil in specified state	10,000
Minimum financial responsibility in amounts if oil spill exceeds minimum quantity of barrels of oil Outer Continental	35,000
Maximum financial responsibility in amounts if oil spill exceeds minimum quantity of barrels of oil	150,000
Approximate asserted claims plus accrued interest assessed by Louisiana Department of Revenue	30,111
Additional estimated assessments including interest by Louisiana Department of Revenue	3,276
Minimum potential range contingency loss	0
Maximum potential range contingency loss	$ 34,000