2.4.0.82202201 - Disclosure - Basis of Presentation (Policies)truefalsefalse1false falsefalseD2013Q2YTDhttp://www.sec.gov/CIK0001407463duration2013-01-01T00:00:002013-06-30T00:00:001true 1us-gaap_AccountingPoliciesAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Accounting Policies [Abstract]2false 2us-gaap_EarningsPerSharePolicyTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;padding-top:12px;text-align:justify;text-indent:32px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"></font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">Net income</font><font style="font-family:inherit;font-size:10pt;"> per common unit is calculated by dividing the limited partners' interest in </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">net income</font><font style="font-family:inherit;font-size:10pt;"> (which excludes net income allocable to unvested participating securities) by the weighted average number of common units outstanding.</font></div><div style="line-height:120%;padding-top:12px;text-align:justify;text-indent:32px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">The Partnership applies the provisions of Accounting Standards Codification ("ASC") Topic 260 "Earnings Per Share" when determining </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">net income</font><font style="font-family:inherit;font-size:10pt;"> per common unit. Instruments granted in unit-based payment transactions that are determined to be participating securities prior to vesting are included in the </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">net income</font><font style="font-family:inherit;font-size:10pt;"> allocation in computing basic and diluted </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">net income</font><font style="font-family:inherit;font-size:10pt;"> per unit under the two-class method. Participating securities represent unvested unit-based compensation awards that have non-forfeitable distribution rights during their vesting periods, such as the phantom units and restricted units awarded under the Pioneer Southwest Energy Partners L.P. 2008 Long Term Incentive Plan (the "LTIP").</font></div><div style="line-height:120%;padding-top:12px;text-align:justify;text-indent:32px;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">The Partnership's </font><font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;">net income</font><font style="font-family:inherit;font-size:10pt;"> is allocated to partners' equity accounts in accordance with the provisions of the First Amended and Restated Agreement of Limited Partnership of Pioneer Southwest Energy Partners L.P. (the "Partnership Agreement").</font></div></div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for computing basic and diluted earnings or loss per share for each class of common stock and participating security. Addresses all significant policy factors, including any antidilutive items that have been excluded from the computation and takes into account stock dividends, splits and reverse splits that occur after the balance sheet date of the latest reporting period but before the issuance of the financial statements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -URI http://asc.fasb.org/subtopic&trid=2144384 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 40 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3630-109257 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 6, 8-16, 60 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false0Net Income Per Common UnitfalseBasis of Presentation (Policies)UnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.pioneersouthwest.com/role/BasisOfPresentationPolicies12