Supplemental Oil And Gas Information (Schedule Of Reserve Value By Category And The Respective Present Values, Before Income Taxes, Discounted At 10% As A Percentage Of Total Proved Reserves) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reserve Quantities [Line Items]
Total proved reserves year-end reserve report	$ 40,417	$ 47,856	$ 53,911
Proved developed producing reserves (PDP)	32,059	34,440	42,626
% of PDP reserves to total proved reserves	79.00%	72.00%	79.00%
Proved developed non-producing reserves	2,956	4,868	3,234
% of PDNP reserves to total proved reserves	7.00%	10.00%	6.00%
Proved undeveloped reserves (PUD)	5,402	8,548	8,051
% of PUD reserves to total proved reserves	14.00%	18.00%	15.00%
Oil [Member]
Reserve Quantities [Line Items]
Total proved reserves year-end reserve report	40,417	47,856	53,906
Proved developed producing reserves (PDP)	32,059	34,440	42,621
% of PDP reserves to total proved reserves	79.00%	72.00%	79.00%
Proved developed non-producing reserves	2,956	4,868	3,234
% of PDNP reserves to total proved reserves	7.00%	10.00%	6.00%
Proved undeveloped reserves (PUD)	5,402	8,548	8,051
% of PUD reserves to total proved reserves	14.00%	18.00%	15.00%
Gas [Member]
Reserve Quantities [Line Items]
Total proved reserves year-end reserve report			5
Proved developed producing reserves (PDP)			5
% of PDP reserves to total proved reserves
Proved developed non-producing reserves
% of PDNP reserves to total proved reserves
Proved undeveloped reserves (PUD)
% of PUD reserves to total proved reserves