Assets Held For Sale And Discontinued Operations (Schedule Of The Amounts In Net Loss From Discontinued Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets Held For Sale And Discontinued Operations [Abstract]
Revenues									$ 22	$ 30	$ 23
Production costs and taxes									(164)	(315)	(260)
Depreciation, depletion, and amortization										(223)	(176)
Impairment										(5,242)
Gain on sale of assets									128
Deferred income tax benefit									(180)	1,419	127
Current income tax benefit									57	20
Net loss from discontinued operations, net of income tax	$ (9)	$ (54)	$ (33)	$ (41)	$ (4,105)	$ (60)	$ (65)	$ (81)	$ (137)	$ (4,311)	$ (286)