2.2.0.7 false Commitments and Contingencies 1110 - Disclosure - Commitments and Contingencies true false false false 1 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDPerShare Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 2 Commitments and Contingencies 0 amag_CommitmentsAndContingenciesDisclosureAbstract amag false na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 3 Commitments and Contingencies 1 us-gaap_CommitmentsAndContingenciesDisclosureTextBlock us-gaap true na duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 <table style="font-size:10pt; font-family:'Times New Roman',times,serif;"> <tr> <td> K.            Commitments and Contingencies   Legal Proceedings   A purported class action complaint was originally filed on March 18, 2010 in the United States District Court for the District of Massachusetts, entitled Silverstrand Investments v. AMAG Pharm., Inc., et. al., Civil Action No. 1:10-CV-10470-NMG, and was amended on September 15, 2010. The amended complaint alleges that we and our President and Chief Executive Officer, Executive Vice President and Chief Financial Officer, our Board of Directors, and certain underwriters in the offering of stock referenced below violated the federal securities laws, specifically Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended, and that our President and Chief Executive Officer and Executive Vice President and Chief Financial Officer violated Section 15 of such Act, respectively, by making certain alleged false and misleading statements and omissions in a registration statement filed in January 2010. The plaintiff seeks unspecified damages on behalf of a purported class of purchasers of our common stock pursuant to our common stock offering on or about January 21, 2010. The Court has not set a trial date for this matter. We believe that the allegations contained in the complaint are without merit and intend to defend the case vigorously. We have not recorded an estimated liability associated with this legal proceeding as we do not believe that such a liability is probable and estimable.   We may periodically become subject to legal proceedings and claims arising in connection with on-going business activities, including claims or disputes related to patents that have been issued or that are pending in the field of research on which we are focused. Other than the complaint described above, we are not aware of any material claims against us at September 30, 2010.</td></tr></table> K.            Commitments and Contingencies   Legal Proceedings   A purported class action false false false us-types:textBlockItemType textblock Includes disclosure of commitments and contingencies. This element may be used as a single block of text to encapsulate the entire disclosure including data and tables. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 14 -Paragraph 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 5 -Paragraph 9, 10, 11, 12 false 1 2 false UnKnown UnKnown UnKnown false true