Legal Proceedings	3 Months Ended
Mar. 31, 2013
Legal Proceedings [Abstract]
Legal Proceedings	Note 9 - Legal Proceedings The information contained in Item 8 - Note 10 in the Company's Annual Report on Form 10-K for the year ended December 31, 2012, is incorporated by reference herein and the defined terms set forth below have the same meaning ascribed to them in that report. There have been no material developments in such legal proceedings, except as set forth below. The Company is or has been a party in a number of lawsuits or proceedings, including the following: Supervisory Goodwill Settlement Agreement – Tax Gross-up - The Company was a plaintiff in a legal proceeding seeking recovery of damages from the United States Government for the loss of the Company's wholly-owned subsidiary, Carteret Savings Bank, F.A. This legal proceeding was commenced in 1993 (the "Supervisory Goodwill" legal proceedings). A Settlement Agreement in the Supervisory Goodwill legal proceedings between the Company, the Federal Deposit Insurance Corporation-Receiver ("FDIC-R") and the Department of Justice ("DOJ") on behalf of the United States of America (the "United States"), was executed (the "Settlement Agreement") which was subject to approval by the United States Court of Federal Claims (the "Court of Federal Claims"). On October 11, 2012, the Court of Federal Claims issued an order approving the Settlement Agreement, and on October 19, 2012, the United States paid $180,650,000 directly to AmBase (the "Settlement Amount"). As part of the Settlement Agreement, the Company is entitled to a tax gross-up in an amount to be determined if and when any federal taxes should be imposed on the Settlement Amount. Based on the Company's 2012 federal income tax return as filed (subject to IRS audit adjustment/review), in March 2013, the Company paid approximately $501,000 of federal income taxes attributable to Alternative Minimum Tax ("AMT") rate calculations. Pursuant to the Settlement Agreement, the Company, on May 3, 2013, filed a Rule 60(b) Motion with the Court of Federal Claims seeking a tax gross-up from the United States for the $501,000, plus applicable tax consequences relative to the reimbursement of this amount. The Company is also: (i) reserving the right to seek a tax gross-up for any additional federal tax which could be owed as a result of additional taxes which may be imposed by the IRS upon tax return review or otherwise; and (ii) is reserving the right to seek the economic value for deductions utilized against the Settlement Award. Pursuant to the Settlement Agreement, Rule 60(b) of the Rules of the Court of Federal Claims will govern the process for receiving a tax gross-up. For additional information, see Note 8 – Income Taxes. Pursuant to the 2007 Employment Agreement, as amended, between the Company and Richard A. Bianco, the Company's Chairman, President and Chief Executive Officer ("Mr. Bianco") (the "2007 Employment Agreement") in 2012, Mr. Bianco was paid an incentive payment of $13.6 million based on the receipt by the Company of the Settlement Amount. An additional amount, to be determined, could be due to Mr. Bianco pursuant to the 2007 Employment Agreement, based on value realized by the Company with respect to a gross-up for federal taxes imposed on the Settlement Amount. As of March 31, 2013, and December 31, 2012, the Company has accrued (but has not paid) approximately $1.9 million of additional compensation expense to Mr. Bianco related to the receivable for the tax gross-up discussed above. The Company has no contingent fee agreements in place with its attorneys or any outside advisor in connection with the Supervisory Goodwill legal proceedings or award. Federal income tax refund suit on Carryback Claims. In March 2000, the Company filed with the IRS several claims and amendments to previously filed claims with respect to the Carryback Claims, seeking refunds from the IRS of alternative minimum tax and other federal income taxes paid by the Company in prior years, plus applicable IRS interest, based on the filing of the 1992 Amended Return. In February 2005, the IRS formally disallowed the Carryback Claims. On April 29, 2008, the Company filed suit with respect to the Carryback Claims in the United States District Court for the District of Connecticut, seeking federal tax refunds for tax year 1989, plus interest. On September 29, 2009, the U.S. Department of Justice (the "DOJ"), representing defendant United States in the suit, filed a Motion to Dismiss. In response, on October 19, 2009, the Company filed its opposition to the DOJ's Motion to Dismiss, as well as the Company's own Motion for Partial Summary Judgment. In June 2010, the Court issued a Memorandum Decision conditionally granting the DOJ's Motion to Dismiss the case but allowing the Company to conduct limited discovery to establish whether the Court has jurisdiction. On August 30, 2010, the Company filed a Motion to Set Aside the Court's Conditional Order of Dismissal. On February 28, 2011, the Court granted the Company's motion and issued a Memorandum of Decision concluding that the Company had timely filed a refund claim for tax year 1992 seeking to adjust the amount of bad debt deduction and that the case should not be dismissed. In March 2011, the Company filed a Motion for Partial Summary Judgment based on the Court's ruling that the Company's refund claims were timely filed. In May 2011, the DOJ filed a Cross Motion for Summary Judgment and an opposition to the Company's Summary Judgment Motion. In June 2011, the Company filed a Memorandum in Opposition to the DOJ's Cross Motion for Summary Judgment and a Reply to the DOJ's Opposition to the Company's Summary Judgment Motion, and the DOJ in June 2011, subsequently filed a response brief. The Court granted the Company's motion in part and denied it in part, in a Memorandum Decision dated November 30, 2011. On January 26, 2012, the Company filed a Motion for Partial Summary Judgment as to the amount of additional bad debt deduction that should be allowed. On February 16, 2012, the DOJ filed an Opposition to the Company's Motion for Partial Summary Judgment. On February 28, 2012, the Company filed a Reply to the DOJ's Opposition to the Company's Motion for Partial Summary Judgment. On May 23, 2012, the Court issued an order denying the Company's Motion for Partial Summary Judgment. Under the Court's rulings, the Company would not be entitled to recover a tax refund. On July 5, 2012, the Court entered its final judgment and order determining that the Company is not entitled to a refund. In December 2012, the Company filed an appeal of the adverse judgment to the United States Court of Appeals for the Second Circuit, where the matter is pending. The parties have filed their briefs and the case is currently scheduled for oral argument on June 10, 2013. The Company can give no assurances as to the final amount of refunds, if any, or when they might be received. The accompanying financial statements include no legal fees in connection with the Carryback Claims proceedings as these legal fees are payable pursuant to a contingent fee arrangement with the attorneys upon a final recovery received. See Note 8 – Income Taxes for further information.

Note 9 - Legal Proceedings

The information contained in Item 8 - Note 10 in the Company's Annual Report on Form 10-K for the year ended December 31, 2012, is incorporated by reference herein and the defined terms set forth below have the same meaning ascribed to them in that report. There have been no material developments in such legal proceedings, except as set forth below.

The Company is or has been a party in a number of lawsuits or proceedings, including the following:

Supervisory Goodwill Settlement Agreement – Tax Gross-up - The Company was a plaintiff in a legal proceeding seeking recovery of damages from the United States Government for the loss of the Company's wholly-owned subsidiary, Carteret Savings Bank, F.A. This legal proceeding was commenced in 1993 (the "Supervisory Goodwill" legal proceedings). A Settlement Agreement in the Supervisory Goodwill legal proceedings between the Company, the Federal Deposit Insurance Corporation-Receiver ("FDIC-R") and the Department of Justice ("DOJ") on behalf of the United States of America (the "United States"), was executed (the "Settlement Agreement") which was subject to approval by the United States Court of Federal Claims (the "Court of Federal Claims"). On October 11, 2012, the Court of Federal Claims issued an order approving the Settlement Agreement, and on October 19, 2012, the United States paid $180,650,000 directly to AmBase (the "Settlement Amount").

As part of the Settlement Agreement, the Company is entitled to a tax gross-up in an amount to be determined if and when any federal taxes should be imposed on the Settlement Amount. Based on the Company's 2012 federal income tax return as filed (subject to IRS audit adjustment/review), in March 2013, the Company paid approximately $501,000 of federal income taxes attributable to Alternative Minimum Tax ("AMT") rate calculations. Pursuant to the Settlement Agreement, the Company, on May 3, 2013, filed a Rule 60(b) Motion with the Court of Federal Claims seeking a tax gross-up from the United States for the $501,000, plus applicable tax consequences relative to the reimbursement of this amount. The Company is also: (i) reserving the right to seek a tax gross-up for any additional federal tax which could be owed as a result of additional taxes which may be imposed by the IRS upon tax return review or otherwise; and (ii) is reserving the right to seek the economic value for deductions utilized against the Settlement Award. Pursuant to the Settlement Agreement, Rule 60(b) of the Rules of the Court of Federal Claims will govern the process for receiving a tax gross-up. For additional information, see Note 8 – Income Taxes.

Pursuant to the 2007 Employment Agreement, as amended, between the Company and Richard A. Bianco, the Company's Chairman, President and Chief Executive Officer ("Mr. Bianco") (the "2007 Employment Agreement") in 2012, Mr. Bianco was paid an incentive payment of $13.6 million based on the receipt by the Company of the Settlement Amount. An additional amount, to be determined, could be due to Mr. Bianco pursuant to the 2007 Employment Agreement, based on value realized by the Company with respect to a gross-up for federal taxes imposed on the Settlement Amount. As of March 31, 2013, and December 31, 2012, the Company has accrued (but has not paid) approximately $1.9 million of additional compensation expense to Mr. Bianco related to the receivable for the tax gross-up discussed above. The Company has no contingent fee agreements in place with its attorneys or any outside advisor in connection with the Supervisory Goodwill legal proceedings or award.

Federal income tax refund suit on Carryback Claims. In March 2000, the Company filed with the IRS several claims and amendments to previously filed claims with respect to the Carryback Claims, seeking refunds from the IRS of alternative minimum tax and other federal income taxes paid by the Company in prior years, plus applicable IRS interest, based on the filing of the 1992 Amended Return. In February 2005, the IRS formally disallowed the Carryback Claims. On April 29, 2008, the Company filed suit with respect to the Carryback Claims in the United States District Court for the District of Connecticut, seeking federal tax refunds for tax year 1989, plus interest. On September 29, 2009, the U.S. Department of Justice (the "DOJ"), representing defendant United States in the suit, filed a Motion to Dismiss. In response, on October 19, 2009, the Company filed its opposition to the DOJ's Motion to Dismiss, as well as the Company's own Motion for Partial Summary Judgment. In June 2010, the Court issued a Memorandum Decision conditionally granting the DOJ's Motion to Dismiss the case but allowing the Company to conduct limited discovery to establish whether the Court has jurisdiction. On August 30, 2010, the Company filed a Motion to Set Aside the Court's Conditional Order of Dismissal. On February 28, 2011, the Court granted the Company's motion and issued a Memorandum of Decision concluding that the Company had timely filed a refund claim for tax year 1992 seeking to adjust the amount of bad debt deduction and that the case should not be dismissed. In March 2011, the Company filed a Motion for Partial Summary Judgment based on the Court's ruling that the Company's refund claims were timely filed. In May 2011, the DOJ filed a Cross Motion for Summary Judgment and an opposition to the Company's Summary Judgment Motion. In June 2011, the Company filed a Memorandum in Opposition to the DOJ's Cross Motion for Summary Judgment and a Reply to the DOJ's Opposition to the Company's Summary Judgment Motion, and the DOJ in June 2011, subsequently filed a response brief. The Court granted the Company's motion in part and denied it in part, in a Memorandum Decision dated November 30, 2011. On January 26, 2012, the Company filed a Motion for Partial Summary Judgment as to the amount of additional bad debt deduction that should be allowed. On February 16, 2012, the DOJ filed an Opposition to the Company's Motion for Partial Summary Judgment. On February 28, 2012, the Company filed a Reply to the DOJ's Opposition to the Company's Motion for Partial Summary Judgment. On May 23, 2012, the Court issued an order denying the Company's Motion for Partial Summary Judgment. Under the Court's rulings, the Company would not be entitled to recover a tax refund. On July 5, 2012, the Court entered its final judgment and order determining that the Company is not entitled to a refund. In December 2012, the Company filed an appeal of the adverse judgment to the United States Court of Appeals for the Second Circuit, where the matter is pending. The parties have filed their briefs and the case is currently scheduled for oral argument on June 10, 2013. The Company can give no assurances as to the final amount of refunds, if any, or when they might be received. The accompanying financial statements include no legal fees in connection with the Carryback Claims proceedings as these legal fees are payable pursuant to a contingent fee arrangement with the attorneys upon a final recovery received. See Note 8 – Income Taxes for further information.