Derivative Activities (Gains (Losses) Of Derivative Contacts By Statement Of Operations Location) (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended	12 Months Ended		0 Months Ended		12 Months Ended				0 Months Ended		12 Months Ended				0 Months Ended	12 Months Ended		0 Months Ended		12 Months Ended								0 Months Ended	12 Months Ended		0 Months Ended		12 Months Ended				0 Months Ended		12 Months Ended
	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010 Commodity Contract [Member]		Dec. 31, 2012 Commodity Contract [Member]		Dec. 31, 2011 Commodity Contract [Member]		Dec. 31, 2010 Interest Rate Contract [Member]		Dec. 31, 2012 Interest Rate Contract [Member]		Dec. 31, 2011 Interest Rate Contract [Member]		Dec. 31, 2010 Realized Gain (Loss) [Member]	Dec. 31, 2012 Realized Gain (Loss) [Member]	Dec. 31, 2011 Realized Gain (Loss) [Member]	Dec. 31, 2010 Realized Gain (Loss) [Member] Commodity Contract [Member]		Dec. 31, 2012 Realized Gain (Loss) [Member] Commodity Contract [Member]		Dec. 31, 2011 Realized Gain (Loss) [Member] Commodity Contract [Member]		Dec. 31, 2012 Realized Gain (Loss) [Member] Interest Rate Contract [Member]		Dec. 31, 2011 Realized Gain (Loss) [Member] Interest Rate Contract [Member]		Dec. 31, 2010 Unrealized Gain (Loss) [Member]	Dec. 31, 2012 Unrealized Gain (Loss) [Member]	Dec. 31, 2011 Unrealized Gain (Loss) [Member]	Dec. 31, 2010 Unrealized Gain (Loss) [Member] Commodity Contract [Member]		Dec. 31, 2012 Unrealized Gain (Loss) [Member] Commodity Contract [Member]		Dec. 31, 2011 Unrealized Gain (Loss) [Member] Commodity Contract [Member]		Dec. 31, 2010 Unrealized Gain (Loss) [Member] Interest Rate Contract [Member]		Dec. 31, 2012 Unrealized Gain (Loss) [Member] Interest Rate Contract [Member]		Dec. 31, 2011 Unrealized Gain (Loss) [Member] Interest Rate Contract [Member]		Dec. 21, 2010 Predecessor [Member]	Dec. 21, 2010 Predecessor [Member] Commodity Contract [Member]		Dec. 21, 2010 Predecessor [Member] Interest Rate Contract [Member]		Dec. 21, 2010 Predecessor [Member] Realized Gain (Loss) [Member]	Dec. 21, 2010 Predecessor [Member] Realized Gain (Loss) [Member] Commodity Contract [Member]		Dec. 21, 2010 Predecessor [Member] Realized Gain (Loss) [Member] Interest Rate Contract [Member]		Dec. 21, 2010 Predecessor [Member] Unrealized Gain (Loss) [Member]	Dec. 21, 2010 Predecessor [Member] Unrealized Gain (Loss) [Member] Commodity Contract [Member]		Dec. 21, 2010 Predecessor [Member] Unrealized Gain (Loss) [Member] Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instrument	$ (13,276)	$ 42,850	$ 18,434	$ (12,682)	[1]	$ 53,071	[1]	$ 47,860	[1]	$ (594)	[2]	$ (10,221)	[2]	$ (29,426)	[2]	$ (289)	$ 27,863	$ (76,565)	$ (289)	[1]	$ 49,800	[1]	$ (72,053)	[1]	$ (21,937)	[2]	$ (4,512)	[2]				$ (12,393)		$ 3,271		$ 119,913								$ 6,163	$ 13,577	[1]	$ (7,414)	[2]	$ 565	$ 5,373	[1]	$ (4,808)	[2]		$ 8,204
Unrealized gain (loss) on derivative instrument	$ (12,987)	$ 14,987	$ 94,999																										$ (12,987)	$ 14,987	$ 94,999	$ (12,393)	[1]	$ 3,271	[1]	$ 119,913	[1]	$ (594)	[2]	$ 11,716	[2]	$ (24,914)	[2]	$ 5,598										$ 5,598	$ 8,204	[1]	$ (2,606)	[2]

[1] Gain (loss) on commodity derivative contracts is located in other income (expense) in the consolidated statements of income

[2] Gain (loss) on interest rate derivative contracts are recorded as part of interest expense and are located in other income (expense) in the consolidated statements of income.