Long-Term Debt (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	1 Months Ended	3 Months Ended
	May 08, 2013	Mar. 31, 2013 Rate	Jan. 15, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Convertible Debt					479.9
PXD Credit Facility [Member]
Debt Instrument [Line Items]
Maximum Borrowing Capacity		1,500
Pioneer Southwest Credit Facility [Member]
Debt Instrument [Line Items]
Maximum Borrowing Capacity		300
Outstanding borrowing		154.0
Unused borrowing capacity		146.0
2.875% Convertible Senior Notes Due 2038 [Member]
Debt Instrument [Line Items]
Convertible Debt		218.6		479.9
Senior notes, interest rate, percentage		2.875%	2.375%		2.875%
Principal amount of notes tendered for conversion		274.1
Shares issued for conversion of debt	115	2,400
Cash Paid To Conversion Of Convertible Senior Notes	12.8	261.3
Stock price in excess of principal amount of note interest rate trigger		120.00%
If Converted [Member] | 2.875% Convertible Senior Notes Due 2038 [Member]
Debt Instrument [Line Items]
Shares issued for conversion of debt		2,100
Cash Paid To Conversion Of Convertible Senior Notes		218.6
Non-Cash [Member] | If Converted [Member] | 2.875% Convertible Senior Notes Due 2038 [Member]
Debt Instrument [Line Items]
Value of shares received for conversion of debt		$ 259.7