Oil And Gas Properties (Narrative) (Details) (USD $)	0 Months Ended	12 Months Ended
	Feb. 06, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Oil And Gas Properties [Line Items]
Proceeds from Divestiture of Businesses	$ 624,000,000
Oil and gas asset retirement costs		(10,334,000)	(37,970,000)	(4,907,000)
Camelot Field [Member]
Oil And Gas Properties [Line Items]
Asset retirement obligation		1,100,000	2,900,000	27,300,000
Asset Retirement Obligation Revision Of Estimate		1,600,000	15,500,000	20,000,000
Gulf Of Mexico Oil And Gas Properties [Member]
Oil And Gas Properties [Line Items]
Oil and gas asset retirement costs		$ (5,200,000)