Long-Term Debt (Details) (USD $)		3 Months Ended			2 Months Ended	3 Months Ended			3 Months Ended
	Mar. 31, 2011 Y	Mar. 31, 2012 PXD Credit Facility [Member]	Mar. 31, 2012 Pioneer Southwest Credit Facility [Member]	May 31, 2008 Pioneer Southwest Credit Facility [Member]	Aug. 31, 2011 2.875% Convertible Senior Notes Due 2038 [Member]	Jun. 30, 2011 2.875% Convertible Senior Notes Due 2038 [Member]	Mar. 31, 2012 2.875% Convertible Senior Notes Due 2038 [Member]	Dec. 31, 2011 2.875% Convertible Senior Notes Due 2038 [Member]	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]
Line of credit facility, maximum borrowing capacity				$ 300,000,000
Line of credit facility, duration (years)	5		5
Outstanding borrowings under the Credit Facility			300,000,000
Outstanding borrowing		67,000,000	50,000,000
Undrawn letters of credit		65,100,000
Unused borrowing capacity		1,100,000,000	250,000,000
Value of shares received for conversion of debt						70,000				386,100,000
Shares issued for conversion of debt					340				3,500,000
Cash received from note holders									479,900,000
Cash Paid To Conversion Of Convertible Senior Notes					71,000
Senior notes, interest rate, percentage							2.875%
Convertible debt							479,900,000	479,900,000
Outstanding borrowings under the Credit Facility		67,000,000	50,000,000
Aggregate loan commitments			300,000,000
Additional maximum amount			$ 100,000,000
Maximum Leverage Ratio			3.5
Future Cash Flows To Total Debt Ratio			1.75