Long-Term Debt (Details) (USD $)	6 Months Ended			1 Months Ended				3 Months Ended	6 Months Ended	1 Months Ended	3 Months Ended				6 Months Ended	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Jul. 31, 2012 PXD Credit Facility [Member]	Jun. 30, 2012 PXD Credit Facility [Member]	Jun. 30, 2012 Pioneer Southwest Credit Facility [Member]	May 31, 2008 Pioneer Southwest Credit Facility [Member]	Jun. 30, 2012 3.95 percent Senior Notes Due 2022 [Member]	Jun. 30, 2012 3.95 percent Senior Notes Due 2022 [Member]	Aug. 31, 2012 2.875% Convertible Senior Notes Due 2038 [Member]	Jun. 30, 2012 2.875% Convertible Senior Notes Due 2038 [Member]	Sep. 30, 2011 2.875% Convertible Senior Notes Due 2038 [Member]	Jun. 30, 2011 2.875% Convertible Senior Notes Due 2038 [Member]	Dec. 31, 2011 2.875% Convertible Senior Notes Due 2038 [Member]	Jun. 30, 2012 Pioneer Southwest Credit Facility [Member] Rate	Mar. 31, 2012 If Converted [Member] 2.875% Convertible Senior Notes Due 2038 [Member]	Mar. 31, 2012 Non-Cash [Member] If Converted [Member] 2.875% Convertible Senior Notes Due 2038 [Member]
Debt Instrument [Line Items]
Outstanding borrowing					$ 110,000,000	$ 69,000,000
Undrawn letters of credit					40,100,000
Unused borrowing capacity					1,100,000,000	231,000,000
Undrawn Letters Of Credit Cancelled				39,000,000
Debt Instrument Covenant, Maximum Leverage Ratio															350.00%
Debt Instrument Covenant, Net Present Value of Cash Flow to Total Debt Ratio															175.00%
Aggregate loan commitments							300,000,000
Senior Notes								600,000,000	600,000,000
Convertible Debt	479,900,000		479,900,000
Senior notes, interest rate, percentage								3.95%	3.95%		2.875%			2.875%
Value of shares received for conversion of debt											22,000		70,000				161,000,000
Shares issued for conversion of debt											50	340				1,800,000
Cash Paid To Conversion Of Convertible Senior Notes										15,000	7,000	71,000
Cash received from note holders																479,900,000
Senior Note Debt Instrument Maturity Date									2022
Debt Instrument, Unamortized Discount								8,500,000	8,500,000
Proceeds from Issuance of Long-term Debt	$ 1,339,093,000	$ 72,610,000						$ 591,500,000