Incentive Plans (Schedule Of Compensation Expense For Each Type Of Incentive Award) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010 employees		Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 53,085,000		$ 45,298,000		$ 38,550,000
Income tax benefit	197,644,000		269,627,000		(83,195,000)
Modification of equity awards per termination agreement			1,300,000
Number of employees affected by the Tunisian divestiture			12
Number of participants effected for unvested equity awards	12
Income from discontinued operations, net of tax	423,152,000		134,050,000		99,716,000
Cash received from stock option exercises	619,000		4,800,000		6,600,000
Restricted Stock-Equity Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	32,861,000	[1]	31,712,000	[1]	31,929,000	[1]
Restricted Stock-Liability Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	10,882,000		4,900,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	2,936,000	[2]	1,522,000	[2]	629,000	[2]
Performance Unit Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	4,500,000		4,635,000		4,868,000
Pioneer Southwest LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	761,000		475,000		217,000
Sendero Series B Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	1,020,000		1,020,000
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	125,000		1,034,000		907,000
Compensation Expense For Incentive Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit	$ 22,084,000		$ 14,019,000		$ 11,675,000

[1] For the year ended December 31, 2010, compensation expense included a charge of $1.3 million for the modification of equity awards associated with termination agreements made with 12 employees affected by the divestiture of the Company's Tunisian subsidiaries. The modification accelerated vesting of all unvested equity awards for the 12 participants to the closing date of the transaction. The $1.3 million charge, net of the associated tax benefit, is included in income from discontinued operations, net of tax, in the accompanying consolidated statement of operations for the year ended December 31, 2010.

[2] Cash proceeds received from stock option exercises during 2011, 2010 and 2009 amounted to $619 thousand, $4.8 million and $6.6 million, respectively.