Acquisitions and Divestitures (Discontinued Operations Narrative) (Details) (USD $)	12 Months Ended								3 Months Ended		12 Months Ended						12 Months Ended						3 Months Ended	12 Months Ended				12 Months Ended			3 Months Ended	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2013 Wolfcamp [Member] Rate	Mar. 31, 2013 Wolfcamp [Member]	Mar. 31, 2013 West Panhandle [Member]	Mar. 31, 2012 Eagle Ford Shale [Member]	Dec. 31, 2013 Other Assets [Member]	Dec. 31, 2012 Other Assets [Member]	Dec. 31, 2011 Other Assets [Member]	Dec. 31, 2012 Barnett Shale Field [Member]	Dec. 31, 2013 Lease Contract for Next 12 Months [Member]	Dec. 31, 2013 Lease Contract for Year 2 [Member]	Dec. 31, 2013 Discontinued Operations [Member]		Dec. 31, 2012 Discontinued Operations [Member]		Dec. 31, 2011 Discontinued Operations [Member]		Sep. 30, 2012 Discontinued Operations [Member] Pioneer Alaska [Member]	Dec. 31, 2013 Discontinued Operations [Member] Pioneer Alaska [Member]	Dec. 31, 2013 Discontinued Operations [Member] Barnett Shale Field [Member]	Dec. 31, 2012 Discontinued Operations [Member] Pioneer South Africa [Member]	Mar. 31, 2012 Discontinued Operations [Member] Pioneer South Africa [Member]	Dec. 31, 2011 Discontinued Operations [Member] Pioneer Tunisia [Member]	Dec. 17, 2013 Pioneer Southwest [Member]	Dec. 31, 2012 Premier Silica [Member]	Dec. 31, 2013 Sendero [Member]	Dec. 31, 2013 Sendero [Member]
Discontinued Operations Assets and Liabilities Included in Assets and Liabilities Held for Sale [Line Items]
Share Per Unit Exchange Ratio																													0.2325
Issuance of treasury stock to acquire outstanding PSE units, shares	3,956,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net																														$ 297,100,000
Proceeds from Divestiture of Interest in Consolidated Subsidiaries																										15,900,000		802,500,000			31,000,000
Tangible Asset Impairment Charges	61,812,000	[1]	5,719,000	[1]	3,126,000	[1]																										25,500,000
Drilling rigs leased															12	8
Gain (Loss) on disposition of assets, net	209,021,000		45,898,000		(3,644,000)		181,300,000		22,400,000	42,600,000	5,300,000	3,300,000	(3,600,000)				8,764,000	[2]	40,735,000	[2]	645,241,000	[2]	12,600,000		8,700,000	28,600,000		645,200,000
Joint Venture Investment Ownership Percentage							40.00%
Significant Acquisitions and Disposals, Acquisition Costs or Sale Proceeds								1,800,000,000																350,600,000			60,000,000
Proceeds from disposition of assets, net of cash sold	711,027,000		95,564,000		819,044,000		623,800,000		38,100,000	54,700,000													10,100,000		33,800,000
Maximum Payments From Related Party For Exploration Drilling And Completion Costs							1,200,000,000
Payments From Related Party For Exploration Drilling And Completion Costs Percent							75.00%
Impairment of oil and gas properties	$ 1,495,242,000		$ 0		$ 354,408,000									$ 532,600,000			$ 729,305,000	[3]	$ 532,589,000	[3]	$ 0	[3]		$ 539,800,000	$ 189,500,000

[1] Represents charges of $36.3 million to reduce excess materials and supplies inventories to their market value and a charge of $25.5 million to reduce the carrying value of Sendero to its estimated fair value. See Notes C and D for additional information on the fair value of Sendero and material and supplies inventory, respectively.

[2] (a)Primarily comprised of Alaskan Petroleum Production Tax credits on qualifying capital expenditures of $38.6 million, $29.3 million and $38.9 million for the years ended December 31, 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.