2.2.0.25falsefalse1100 - Disclosure - Equitytruefalsefalse1falsefalseUSDfalsefalse1/1/2011 - 3/31/2011 USD ($) USD ($) / shares $D2011Q1http://www.sec.gov/CIK0001166036duration2011-01-01T00:00:002011-03-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDPerShareDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2true0mwe_EquityDisclosureAbstractmwefalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseEquity3false0us-gaap_PartnersCapitalNotesDisclosureTextBlockus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00<table style="font-size:10pt; font-family:'Times New Roman',times,serif;"> <tr> <td> 10. Equity <ul> <li style="list-style: none"> Equity Offering</li></ul>         On January 14, 2011, the Partnership completed a public offering of approximately 3.45 million newly issued common units representing limited partner interests, which includes the full exercise of the underwriters' over-allotment option, at a price of $41.20 per common unit. Net proceeds of approximately $138.2 million were used to partially fund the Partnership's ongoing capital expenditure program, including a portion of the costs associated with the Langley Acquisition (see Note 3). <ul> <li style="list-style: none"> Distributions of Available Cash</li></ul> <div style="PADDING-RIGHT: 0pt; PADDING-LEFT: 0pt; PADDING-BOTTOM: 0pt; MARGIN-LEFT: 20%; WIDTH: 60%; PADDING-TOP: 0pt; POSITION: relative">   <div align="center"> <table cellspacing="0" cellpadding="0" width="100%" border="0"> <tr style="HEIGHT: 0px"> <td style="FONT-FAMILY: times" align="left"></td> <td style="FONT-FAMILY: times" width="12"></td> <td style="FONT-FAMILY: times" align="right" width="7"></td> <td style="FONT-FAMILY: times" width="86"></td> <td style="FONT-FAMILY: times" width="12"></td> <td style="FONT-FAMILY: times" align="right" width="7"></td> <td style="FONT-FAMILY: times" width="97"></td> <td style="FONT-FAMILY: times" width="12"></td> <td style="FONT-FAMILY: times" align="right" width="7"></td> <td style="FONT-FAMILY: times" width="103"></td> <td style="FONT-FAMILY: times" width="12"></td></tr> <tr style="HEIGHT: 0px" valign="bottom"> <th style="FONT-FAMILY: times" nowrap="nowrap" align="left"> <div style="MARGIN-BOTTOM: 0pt; WIDTH: 53pt; BORDER-BOTTOM: #000000 1pt solid">Quarter Ended </div></th> <th style="FONT-FAMILY: times"> </th> <th style="BORDER-BOTTOM: #000000 1pt solid; FONT-FAMILY: times" align="center" colspan="2">Distribution Per Common Unit </th> <th style="FONT-FAMILY: times"> </th> <th style="BORDER-BOTTOM: #000000 1pt solid; FONT-FAMILY: times" align="center" colspan="2">Record Date </th> <th style="FONT-FAMILY: times"> </th> <th style="BORDER-BOTTOM: #000000 1pt solid; FONT-FAMILY: times" align="center" colspan="2">Payment Date </th> <th style="FONT-FAMILY: times"> </th></tr> <tr style="HEIGHT: 0px" valign="top" bgcolor="#CCEEFF"> <td style="FONT-FAMILY: times" valign="bottom"> March 31, 2011</td> <td style="FONT-FAMILY: times" valign="bottom"> </td> <td style="FONT-FAMILY: times" valign="bottom" align="right">$</td> <td style="FONT-FAMILY: times" valign="bottom" align="right">0.67</td> <td style="FONT-FAMILY: times" valign="bottom"> </td> <td style="FONT-FAMILY: times" valign="bottom"> </td> <td style="FONT-FAMILY: times" valign="bottom" align="right">May 2, 2011</td> <td style="FONT-FAMILY: times" valign="bottom"> </td> <td style="FONT-FAMILY: times" valign="bottom"> </td> <td style="FONT-FAMILY: times" valign="bottom" align="right">May 13, 2011</td> <td style="FONT-FAMILY: times" valign="bottom"> </td></tr> <tr style="HEIGHT: 0px" valign="top" bgcolor="white"> <td style="FONT-FAMILY: times" valign="bottom"> December 31, 2010</td> <td style="FONT-FAMILY: times" valign="bottom"> </td> <td style="FONT-FAMILY: times" valign="bottom" align="right">$</td> <td style="FONT-FAMILY: times" valign="bottom" align="right">0.65</td> <td style="FONT-FAMILY: times" valign="bottom"> </td> <td style="FONT-FAMILY: times" valign="bottom"> </td> <td style="FONT-FAMILY: times" valign="bottom" align="right">February 7, 2011</td> <td style="FONT-FAMILY: times" valign="bottom"> </td> <td style="FONT-FAMILY: times" valign="bottom"> </td> <td style="FONT-FAMILY: times" valign="bottom" align="right">February 14, 2011</td> <td style="FONT-FAMILY: times" valign="bottom"> </td></tr></table></div> </div></td></tr></table> 10. Equity Equity Offering         On January 14, 2011, the Partnership completed a public offering offalsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDescribes the formation, structure, control and ownership of the partnership. Disclosures related to accounts comprising partners' capital. Includes balances of general partners' capital account, limited partners' capital account, preferred partners' capital account and total partners' capital account and units outstanding; accumulated other comprehensive income; amount and nature of changes to amount of partner's capital and units outstanding by class, rights and privileges for each class of units; distribution policies and distributions paid by unit class; impact of and correction of an error in previously issued financial statements; limitations of partners' liability; redemption, conversion and distribution policies; and deferred compensation related to the issuance of units.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Practice Bulletin (PB) -Number 14 -Paragraph 10, 15 falsefalseEquity12EquityUnKnownUnKnownUnKnownUnKnownfalsetrue