Net Income (Loss) Per Share Attributable To Common Stockholders (Reconciliation Of Earnings Attributable To Common Stockholders, Basic And Diluted) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Statement Operating Activities Segment [Line Items]
Income (loss) from continuing operations, net of tax	$ (388,809)		$ 496,495		$ 360,365
Income (loss) as reported, Discontinued Operations	(449,605)		(304,210)		474,124
Income (loss) as reported	(838,414)		192,285		834,489
Participating basic earnings	(130)	[1]	(3,029)	[1]	(15,178)	[1]
Basic income (loss) attributable to common stockholders	(838,544)		189,256		819,311
Reallocation of participating earnings	0	[1]	161	[1]	385	[1]
Diluted income (loss) attributable to common stockholders	(838,544)		189,417		819,696
Segment, Continuing Operations [Member]
Statement Operating Activities Segment [Line Items]
Income (loss) from continuing operations, net of tax	(388,809)		496,495		360,365
Participating basic earnings	(60)	[1]	(2,160)	[1]	(6,554)	[1]
Basic income (loss) attributable to common stockholders	(388,869)		494,335		353,811
Reallocation of participating earnings	0	[1]	115	[1]	166	[1]
Diluted income (loss) attributable to common stockholders	(388,869)		494,450		353,977
Discontinued Operations [Member]
Statement Operating Activities Segment [Line Items]
Income (loss) as reported, Discontinued Operations	(449,605)		(304,210)		474,124
Participating basic earnings	(70)	[1]	(869)	[1]	(8,624)	[1]
Basic income (loss) attributable to common stockholders	(449,675)		(305,079)		465,500
Reallocation of participating earnings	0	[1]	46	[1]	219	[1]
Diluted income (loss) attributable to common stockholders	$ (449,675)		$ (305,033)		$ 465,719

[1] (a)Unvested restricted stock awards and Pioneer Southwest phantom unit awards (prior to the December 2013 Pioneer Southwest merger) represent participating securities because they participate in nonforfeitable dividends or distributions with the common equity owners of the Company or Pioneer Southwest, as applicable. Participating share- or unit-based earnings represent the distributed and undistributed earnings of the Company attributable to the participating securities. Unvested restricted stock awards and phantom unit awards do not participate in undistributed net losses as they are not contractually obligated to do so.