Related Party Transactions - Payments Recieved from (paid to) JEX and REX during Specific Transactions (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
REX [Member]
Related Party Transaction [Line Items]
Reimbursement of certain costs	$ 0	$ (10)
Prospect fees	0	0
Under advisory agreement dated April 1, 2012	0	0
REX distribution to members	323	0
Juneau Exploration LLC [Member]
Related Party Transaction [Line Items]
Reimbursement of certain costs	(146)	(5)
Prospect fees	0	(250)
Under advisory agreement dated April 1, 2012	(667)	0
REX distribution to members	$ 0	$ 0