ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	3 Months Ended		9 Months Ended					9 Months Ended	1 Months Ended	9 Months Ended	1 Months Ended					1 Months Ended				1 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 item	Mar. 31, 2012	Jun. 30, 2012	Feb. 02, 2012	Jun. 30, 2011	Mar. 31, 2013 3D Seismic Contract with Veritas sqkm	Oct. 31, 2012 AGR Peak Well Management Ltd AGR Lawsuit	Mar. 31, 2013 AGR Peak Well Management Ltd AGR Lawsuit	Dec. 31, 2012 SCS	Dec. 31, 2012 SCS Minimum m	Mar. 31, 2013 Dana	Mar. 31, 2013 Tullow Guinea Ltd	Nov. 20, 2012 Tullow Guinea Ltd	Dec. 31, 2012 Guinea concession	Mar. 31, 2013 Guinea concession	Dec. 30, 2012 Guinea concession	Feb. 29, 2012 Guinea concession	Feb. 29, 2012 Sabu-1 well m item	Mar. 31, 2013 Sabu-1 well
Nature of business
Number of wholly-owned subsidiaries			3
Status of our Business
Ownership interest sold (as a percent)											40.00%
Consideration of sale of interest in PSC											$ 27,000,000
Depth of exploration well to be drilled												2,000
Gross expenditure for an exploration well to be paid by Tullow as additional consideration											100,000,000
Percentage of participating interest share of costs associated with the concession obligated to be paid															40.00%
Gross expenditure for an appraisel well to be paid by Tullow as additional consideration											100,000,000
Area of 3D seismic survey acquired								4,000
Period through which additional consideration is to be paid by Tullow											90 days
Transaction costs			3,128,000								3,100,000
Expected total cost for acquiring the survey, processing and other services																28,000,000
Gross remaining costs to be paid for the most recent 3D seismic survey based on current ownership interest																600,000
Net remaining costs to be paid for the most recent 3D seismic survey based on current ownership interest																200,000
Number of exploratory wells drilled																				1
Share of entity in total amount paid on gross basis										82,900,000											87,500,000
Ownership interest (as a percent)													23.00%	40.00%			37.00%	77.00%	77.00%
Planned total depth of drilled well reached																				3,600
Cost incurred on drilled well																				126,400,000
Cost incurred for interest of entity																				97,300,000
Total amount paid on gross basis										107,600,000											113,600,000
Additional amount seeks on a gross basis									9,500,000	9,500,000
Share of entity in additional amount seeks on a gross basis									7,300,000	7,300,000
Cash	41,628,000	44,197,000	41,628,000	44,197,000	37,148,000		79,889,000
Available-for-sale securities	5,085,000		5,085,000
Restricted cash held in escrow in connection with our drilling contract with AGR	19,187,000		19,187,000		19,180,000
Liabilities	24,370,000		24,370,000		26,729,000
Current liabilities	24,267,000		24,267,000		26,604,000
Noncurrent liabilities	103,000		103,000		125,000
Other commitments	0		0
Allowance for doubtful accounts	$ 0		$ 0		$ 0
Earnings per Share
Common shares that can be purchased upon exercise of options	10,100,000	10,700,000	10,100,000	10,700,000
Average exercise price of common stock (in dollars per share)	$ 1.83	$ 2.29	$ 1.83	$ 2.29
Warrants that can be purchased	13,500,000	13,400,000	13,500,000	13,400,000		10,000,000
Average exercise price of warrants (in dollars per share)	$ 2.93	$ 2.94	$ 2.93	$ 2.94		$ 3.50
Common shares that can be purchased using the treasury stock method, had there been net income	200,000	2,600,000	400,000	3,400,000
Common shares that can be purchased using the treasury stock method, had there been net income		1,600,000		2,300,000