Interest And Other Income (Components Of Interest And Other Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Interest and Other Income [Abstract]
Equity interest in income of unconsolidated affiliate	$ 7,861	[1]	$ 502	[1]	$ 14,842	[1]	$ 801	[1]
Alaskan Petroleum Production Tax credits and refunds	0	[2]	0	[2]	11,846	[2]	27,452	[2]
Third-party income from vertical integration services	(3,820)	[3]	8,881	[3]	2,729	[3]	7,913	[3]
Other income	592		3,698		2,234		4,334
Deferred compensation plan income	150		299		1,523		1,166
Interest income	1,260		214		1,317		401
Total interest and other income	$ 6,043		$ 13,594		$ 34,491		$ 42,067

[1] Represents the Company's equity in the earnings of EFS Midstream LLC ("EFS Midstream"), which owns and operates gas and liquids gathering, treating and transportation assets in the Eagle Ford Shale area of South Texas.

[2] The Company earns Alaskan Petroleum Production Tax ("PPT") credits on qualifying capital expenditures. The Company recognizes income from PPT credits when they are realized through cash refunds or as reductions in production and ad valorem taxes if realizable as offsets to PPT expense.

[3] Third-party income (loss) from vertical integration services represents third-party working interests' share of earnings associated with Company-provided fracture stimulation, drilling and related services.