Contingencies and litigations (Details) (USD $)	3 Months Ended
	Dec. 31, 2009	Feb. 14, 2012	Mar. 31, 2011	Jan. 31, 2006
Contingencies and litigations
Acutal damages found by jury in millions	66.5
Actual damages in tortous interference claim millions	31.16
Exemplary damages and individual and Eurenergy millions	8.5
reinstated the jury award of actual damages jointly and severely against The individual and EurEnergy millions		66.5
received an invoice from Chesapeake				$ 556,217
Chesapeake received a summary judgment award			686,874
Legal fees.	$ 65,000