Discontinued Operations (Summarized Financial Results for Discontinued Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of natural gas and oil properties	$ (8,410)	$ 0
Income (loss) from discontinued operations, net of income taxes	0	(682)
Rexer Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		0
Operating expenses		(10)
Impairment of natural gas and oil properties		(1,031)
Exploration expenses		(8)
Loss before income taxes		(1,049)
Benefit (provision) for income taxes		367
Income (loss) from discontinued operations, net of income taxes		$ (682)