Subsequent Events	3 Months Ended
Mar. 31, 2013
Subsequent Events [Abstract]
Subsequent Events	Subsequent Event In April 2013, Pioneer Southwest declared a cash distribution of $0.52 per common unit for the period from January 1 to March 31, 2013. The distribution is payable on May 10, 2013 to unitholders of record at the close of business on May 3, 2013. Associated therewith, Pioneer Southwest expects to pay $18.6 million of aggregate distributions. On April 15, 2013, the Company announced that it would exercise its option to redeem all Convertible Senior Notes that have not been converted by the holders before May 16, 2013 for cash at a price equal to the full principal amount plus accrued and unpaid interest, in accordance with the indenture agreement. The Convertible Senior Notes are convertible at the option of the holders prior to May 16, 2013, using a net share settlement process, into a combination of cash and shares of the Company's common stock based on a formula set forth in the indenture supplement. See Note G for additional information about the Convertible Senior Notes. On May 7, 2013, the Company delivered a proposal to the chairman of the Conflicts Committee (the "Conflicts Committee") of the General Partner to acquire all of the outstanding common units of Pioneer Southwest that are held by unitholders other than Pioneer or its subsidiaries for consideration of .2234 of a share of common stock of Pioneer for each outstanding common unit of Pioneer Southwest held by such unitholders in a transaction to be structured as a merger of Pioneer Southwest with a wholly-owned subsidiary of Pioneer. In proposing the .2234 exchange ratio, the Company stated that it has assumed that a regular quarterly common unit distribution of $0.52 per common unit will be declared by Pioneer Southwest in July 2013 and that, thereafter, common unit distributions will be suspended while the transaction is pending. The consummation of the transactions contemplated by the Company's proposal is subject to approval of the Company's board of directors, approval of the Conflicts Committee and the negotiation of a definitive agreement. There can be no assurance that a definitive agreement will be executed or that any transaction will be approved or consummated.

Subsequent Event

In April 2013, Pioneer Southwest declared a cash distribution of $0.52 per common unit for the period from January 1 to March 31, 2013. The distribution is payable on May 10, 2013 to unitholders of record at the close of business on May 3, 2013. Associated therewith, Pioneer Southwest expects to pay $18.6 million of aggregate distributions.

On April 15, 2013, the Company announced that it would exercise its option to redeem all Convertible Senior Notes that have not been converted by the holders before May 16, 2013 for cash at a price equal to the full principal amount plus accrued and unpaid interest, in accordance with the indenture agreement. The Convertible Senior Notes are convertible at the option of the holders prior to May 16, 2013, using a net share settlement process, into a combination of cash and shares of the Company's common stock based on a formula set forth in the indenture supplement. See Note G for additional information about the Convertible Senior Notes.

On May 7, 2013, the Company delivered a proposal to the chairman of the Conflicts Committee (the "Conflicts Committee") of the General Partner to acquire all of the outstanding common units of Pioneer Southwest that are held by unitholders other than Pioneer or its subsidiaries for consideration of .2234 of a share of common stock of Pioneer for each outstanding common unit of Pioneer Southwest held by such unitholders in a transaction to be structured as a merger of Pioneer Southwest with a wholly-owned subsidiary of Pioneer. In proposing the .2234 exchange ratio, the Company stated that it has assumed that a regular quarterly common unit distribution of $0.52 per common unit will be declared by Pioneer Southwest in July 2013 and that, thereafter, common unit distributions will be suspended while the transaction is pending. The consummation of the transactions contemplated by the Company's proposal is subject to approval of the Company's board of directors, approval of the Conflicts Committee and the negotiation of a definitive agreement. There can be no assurance that a definitive agreement will be executed or that any transaction will be approved or consummated.