2.4.0.81040 - Disclosure - Restricted Cashtruefalsefalse1false falsefalseD2013Q2YTDhttp://www.sec.gov/CIK0001235010duration2013-01-01T00:00:002013-06-30T00:00:001true 1us-gaap_RestrictedCashAndInvestmentsNoncurrentAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Restricted Cash2false 2us-gaap_RestrictedAssetsDisclosureTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div style="font-size:10.0pt;font-family:Times New Roman;"> <p style="TEXT-INDENT: -1.2in; MARGIN: 0in 0in 0pt 1.2in;"><b><font style="FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt; FONT-WEIGHT: bold;" size="2">4. Restricted Cash</font></b></p> <p style="TEXT-INDENT: -1.2in; MARGIN: 0in 0in 0pt 1.2in;">&#160;</p> <p style="TEXT-INDENT: 0.25in; MARGIN: 0in 0in 0pt;"><font style="FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt;" size="2">The Company designated $17.5&#160;million as collateral for a security bond posted in the litigation against Amphastar Pharmaceuticals&#160;Inc., or Amphastar, Actavis,&#160;Inc., or Actavis (formerly Watson Pharmaceuticals&#160;Inc.), and International Medical Systems,&#160;Ltd. (a wholly owned subsidiary of Amphastar), as discussed within Note&#160;8, <i>Legal Contingencies</i>. The $17.5&#160;million is held in an escrow account by Hanover Insurance. The Company classified this restricted cash as long-term as the timing of a final decision in the Enoxaparin Sodium Injection patent litigation is not known.</font></p> <p style="TEXT-INDENT: 0.25in; MARGIN: 0in 0in 0pt;">&#160;</p> <p style="TEXT-INDENT: 0.25in; MARGIN: 0in 0in 0pt;"><font style="FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt;" size="2">The Company designated $2.5&#160;million as collateral for a letter of credit related to the lease of office and laboratory space located at 675 West Kendall Street in Cambridge, Massachusetts. This balance will remain restricted through the remaining term of the lease which ends in April&#160;2015. The Company will earn interest on the balance.</font></p> <p style="MARGIN: 0in 0in 0pt;">&#160;</p> </div>falsefalsefalsenonnum:textBlockItemTypenaThe entire disclosure for assets that are restricted in their use, generally by contractual agreements or regulatory requirements. This would include, but not limited to, a description of the restricted assets and the terms of the restriction.No definition available.false0Restricted CashfalseRestricted CashUnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.momentapharma.com/role/DisclosureRestrictedCash12