Property And Equipment, Net (Schedule Of Property And Equipment) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Proved oil and gas properties	$ 2,182,226	$ 1,713,827
Accumulated depreciation, depletion and amortization	(773,742)	(561,279)
Proved oil and gas properties, net	1,408,484	1,152,548
Unproved properties, not being amortized
Unevaluated leasehold and seismic costs	302,232	238,833
Exploratory wells in progress	30,196	43,803
Capitalized interest	45,009	41,052
Total unproved properties, not being amortized	377,437	323,688
Other property and equipment	15,260	17,079
Accumulated depreciation	(6,966)	(5,641)
Other property and equipment, net	8,294	11,438
TOTAL PROPERTY AND EQUIPMENT, NET	$ 1,794,215	$ 1,487,674