Segment and Geographical Data (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 30, 2012 segment	Sep. 30, 2011
Segment Reporting Information [Line Items]
Number of Reportable Segments	2
Revenues	$ 1,660	$ 3,735
Consolidated net income (loss)	(5,310)	940
Nautilus Poplar, LLC (NP)
Segment Reporting Information [Line Items]
Revenues	1,460	1,231
Consolidated net income (loss)	(272)	3,868
Magellan Petroleum Australia Limited (MPAL)
Segment Reporting Information [Line Items]
Revenues	200	2,504
Consolidated net income (loss)	(1,824)	(932)
Corporate
Segment Reporting Information [Line Items]
Revenues	0	0
Consolidated net income (loss)	(3,043)	(1,993)
Inter-segment Elimination
Segment Reporting Information [Line Items]
Revenues	0	0
Consolidated net income (loss)	$ (171)	$ (3)