Basis Of Presentation (Stock-Based Awards, Lapses, Exercises And Forfeitures) (Details)	3 Months Ended						3 Months Ended
	Mar. 31, 2012 Restricted Stock Equity Awards [Member]	Mar. 31, 2012 Restricted Stock Liability Awards [Member]	Mar. 31, 2012 Performance Units [Member]	Mar. 31, 2012 Stock Options [Member]	Mar. 31, 2012 Pioneer Southwest LTIP Restricted Units [Member]	Dec. 31, 2011 Pioneer Southwest LTIP Restricted Units [Member]	Mar. 31, 2012 Pioneer Southwest LTIP Phantom Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at beginning of period	1,857,612	322,925	114,128	564,044	7,492	7,492	65,157
Awards granted	834,210	216,964	47,875	98,819			37,487
Awards vested	(1,184,811)	(115,245)
Options exercised				(64,509)
Awards forfeited	(2,575)	(2,383)
Outstanding at end of period	1,504,436	422,261	162,003	598,354	7,492	7,492	102,644