Exploratory Well Costs (Capitalized Exploratory Well And Project Activity) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Increase (Decrease) in Capitalized Exploratory Well Costs that are Pending Determination of Proved Reserves [Roll Forward]
Capitalized Exploratory Well Costs, Beginning Balance	$ 212,670	[1]	$ 107,596	[1]	$ 96,193
Capitalized Exploratory Well Cost, Additions Pending Determination of Proved Reserves	1,219,797		926,084		524,313
Reclassification due to determination of proved reserves	(1,044,815)		(790,373)		(480,716)
Capitalized Exploratory Well Cost Assets Disposition	(92,855)		0		(28,938)
Impairment of oil and gas properties	1,495,242		0		354,408
Exploratory well costs charged to exploration expense	(49,134)	[2]	(30,637)	[2]	(3,256)	[2]
Capitalized Exploratory Well Costs, Ending Balance	158,902	[1]	212,670	[1]	107,596	[1]
Exploration Abandonment and Impairment Expense	98,448		98,285		80,691
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net	526,148
Discontinued Operations [Member]
Increase (Decrease) in Capitalized Exploratory Well Costs that are Pending Determination of Proved Reserves [Roll Forward]
Impairment of oil and gas properties	729,305	[3]	532,589	[3]	0	[3]
Exploration Abandonment and Impairment Expense	52,707		108,076		44,898
Capitalized exploratory costs [Member]
Increase (Decrease) in Capitalized Exploratory Well Costs that are Pending Determination of Proved Reserves [Roll Forward]
Impairment of oil and gas properties	(86,761)		0		0
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net	60,300
Capitalized exploratory costs [Member] | Discontinued Operations [Member]
Increase (Decrease) in Capitalized Exploratory Well Costs that are Pending Determination of Proved Reserves [Roll Forward]
Exploration Abandonment and Impairment Expense	$ 43,300		$ 21,600		$ 180

[1] Includes $60.3 million of capitalized exploratory well costs classified as held for sale in the accompanying consolidated balance sheet as of December 31, 2013.

[2] Includes exploration and abandonment expense reclassified as discontinued operations of $43.3 million, $21.6 million, and $180 thousand in 2013, 2012 and 2011, respectively.

[3] (c)Represents a noncash impairment charge of $539.8 million on Pioneer Alaska net assets during the year ended December 31, 2013 and noncash impairment charges of $189.5 million and $532.6 million during the years ended December 31, 2013 and 2012, respectively, on the Company's net assets in the Barnett Shale field. See Note D for additional information regarding the noncash impairment charges.