Supplemental Oil And Gas Information (Schedule Of Results Of Operations From Oil And Gas Producing Activities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Supplemental Oil And Gas Information [Abstract]
Revenues	$ 19,885	$ 16,862	$ 12,876
Production costs and taxes	(5,610)	(5,310)	(5,308)
Depreciation, depletion and amortization	(3,044)	(2,195)	(1,938)
Income from oil and gas producing activities	$ 11,231	$ 9,357	$ 5,630