Long-Term Debt	6 Months Ended
Jun. 30, 2011
Long-Term Debt
Long-Term Debt	NOTE F. Long-term Debt *Credit Facility.* During March 2011, the Company entered into a Second Amended and Restated 5-Year Revolving Credit Agreement (the "Credit Facility") with a syndicate of financial institutions that matures in March 2016, unless extended in accordance with the terms of the Credit Facility. The Credit Facility replaces the Company's Amended and Restated 5-Year Revolving Credit Agreement entered into in April 2007 (the "Expired Credit Facility") and provides for aggregate loan commitments of $1.25 billion. As of June 30, 2011, the Company had no outstanding borrowings under the Credit Facility and $65.1 million of undrawn letters of credit, all of which were commitments under the Credit Facility, leaving the Company with $1.2 billion of unused borrowing capacity under the Credit Facility. Borrowings under the Credit Facility may be in the form of revolving loans or swing line loans. Aggregate outstanding swing line loans may not exceed $150 million. Revolving loans under the Credit Facility bear interest, at the option of the Company, based on (a) a rate per annum equal to the higher of the prime rate announced from time to time by Wells Fargo Bank, National Association or the weighted average of the rates on overnight Federal funds transactions with members of the Federal Reserve System during the last preceding business day plus 0.5 percent plus a defined alternate base rate spread margin ("ABR Margin"), which is currently one percent based on the Company's debt rating or (b) a base Eurodollar rate, substantially equal to LIBOR, plus a margin (the "Applicable Margin"), which is currently two percent and is also determined by the Company's debt rating. Swing line loans under the Credit Facility bear interest at a rate per annum equal to the "ASK" rate for Federal funds periodically published by the Dow Jones Market Service plus the Applicable Margin. Letters of credit outstanding under the Credit Facility are subject to a per annum fee, representing the Applicable Margin plus 0.125 percent. The Company also pays commitment fees on undrawn amounts under the Credit Facility that are determined by the Company's debt rating (currently 0.375 percent). The Credit Facility contains certain financial covenants, which include the maintenance of a ratio of total debt to book capitalization less intangible assets, accumulated other comprehensive income and certain noncash asset impairments not to exceed .60 to 1.0. The covenants also include the maintenance of a ratio of the net present value of the Company's oil and gas properties to total debt of at least1.75 to 1.0 until the Company achieves an investment grade rating by Moody's Investors Service, Inc. or Standard & Poors Ratings Group, Inc. As of June 30, 2011, the Company and Pioneer Southwest were in compliance with all of their debt covenants. In accordance with GAAP, the Company accounted for the entry into the Credit Facility as an extinguishment of the Expired Credit Facility. Associated therewith, the Company recorded a $2.4 million loss on extinguishment of debt to write off the unamortized issuance costs of the Company's Expired Credit Facility, which is included in other expense in the accompanying consolidated statement of operations for the six months ended June 30, 2011 (see Note P). *Convertible senior notes.* As of June 30, 2011 and December 31, 2010, the Company had $480 million of 2.875% Convertible Senior Notes outstanding. The 2.875% Convertible Senior Notes are convertible under certain circumstances, using a net share settlement process, into a combination of cash and the Company's common stock pursuant to a formula. The Company's stock price during March 2011 caused the Company's 2.875% Convertible Senior Notes to become convertible at the option of the holders during the three months ended June 30, 2011. Associated therewith, holders of the 2.875% Convertible Senior Notes tendered $70 thousand principal amount of the notes for conversion during the three months ended June 30, 2011. During July and August 2011, the Company paid the holders a total of $71 thousand of cash and issued 340 shares of the Company's common stock. During June 2011, the Company's stock price performance did not qualify the 2.875% Convertible Senior Notes for conversion at the option of the holders for the three months ended September 30, 2011. The Company's 2.875% Convertible Senior Notes may become convertible in future quarters depending on the Company's stock price performance or under certain other conditions. If all of the 2.875% Convertible Senior Notes had been converted on June 30, 2011, the note holders would have received $479.9 million of cash and approximately 1.8 million shares of the Company's common stock, which was calculated over the last 20 trading days of June and valued at $158.8 million.

Long-Term Debt

6 Months Ended

Jun. 30, 2011

NOTE F. Long-term Debt

Credit Facility. During March 2011, the Company entered into a Second Amended and Restated 5-Year Revolving Credit Agreement (the "Credit Facility") with a syndicate of financial institutions that matures in March 2016, unless extended in accordance with the terms of the Credit Facility. The Credit Facility replaces the Company's Amended and Restated 5-Year Revolving Credit Agreement entered into in April 2007 (the "Expired Credit Facility") and provides for aggregate loan commitments of $1.25 billion. As of June 30, 2011, the Company had no outstanding borrowings under the Credit Facility and $65.1 million of undrawn letters of credit, all of which were commitments under the Credit Facility, leaving the Company with $1.2 billion of unused borrowing capacity under the Credit Facility.

Borrowings under the Credit Facility may be in the form of revolving loans or swing line loans. Aggregate outstanding swing line loans may not exceed $150 million. Revolving loans under the Credit Facility bear interest, at the option of the Company, based on (a) a rate per annum equal to the higher of the prime rate announced from time to time by Wells Fargo Bank, National Association or the weighted average of the rates on overnight Federal funds transactions with members of the Federal Reserve System during the last preceding business day plus 0.5 percent plus a defined alternate base rate spread margin ("ABR Margin"), which is currently one percent based on the Company's debt rating or (b) a base Eurodollar rate, substantially equal to LIBOR, plus a margin (the "Applicable Margin"), which is currently two percent and is also determined by the Company's debt rating. Swing line loans under the Credit Facility bear interest at a rate per annum equal to the "ASK" rate for Federal funds periodically published by the Dow Jones Market Service plus the Applicable Margin. Letters of credit outstanding under the Credit Facility are subject to a per annum fee, representing the Applicable Margin plus 0.125 percent. The Company also pays commitment fees on undrawn amounts under the Credit Facility that are determined by the Company's debt rating (currently 0.375 percent). The Credit Facility contains certain financial covenants, which include the maintenance of a ratio of total debt to book capitalization less intangible assets, accumulated other comprehensive income and certain noncash asset impairments not to exceed .60 to 1.0. The covenants also include the maintenance of a ratio of the net present value of the Company's oil and gas properties to total debt of at least1.75 to 1.0 until the Company achieves an investment grade rating by Moody's Investors Service, Inc. or Standard & Poors Ratings Group, Inc.

As of June 30, 2011, the Company and Pioneer Southwest were in compliance with all of their debt covenants.

In accordance with GAAP, the Company accounted for the entry into the Credit Facility as an extinguishment of the Expired Credit Facility. Associated therewith, the Company recorded a $2.4 million loss on extinguishment of debt to write off the unamortized issuance costs of the Company's Expired Credit Facility, which is included in other expense in the accompanying consolidated statement of operations for the six months ended June 30, 2011 (see Note P).

Convertible senior notes. As of June 30, 2011 and December 31, 2010, the Company had $480 million of 2.875% Convertible Senior Notes outstanding. The 2.875% Convertible Senior Notes are convertible under certain circumstances, using a net share settlement process, into a combination of cash and the Company's common stock pursuant to a formula.

The Company's stock price during March 2011 caused the Company's 2.875% Convertible Senior Notes to become convertible at the option of the holders during the three months ended June 30, 2011. Associated therewith, holders of the 2.875% Convertible Senior Notes tendered $70 thousand principal amount of the notes for conversion during the three months ended June 30, 2011. During July and August 2011, the Company paid the holders a total of $71 thousand of cash and issued 340 shares of the Company's common stock.

During June 2011, the Company's stock price performance did not qualify the 2.875% Convertible Senior Notes for conversion at the option of the holders for the three months ended September 30, 2011. The Company's 2.875% Convertible Senior Notes may become convertible in future quarters depending on the Company's stock price performance or under certain other conditions. If all of the 2.875% Convertible Senior Notes had been converted on June 30, 2011, the note holders would have received $479.9 million of cash and approximately 1.8 million shares of the Company's common stock, which was calculated over the last 20 trading days of June and valued at $158.8 million.