Organization	3 Months Ended
Mar. 31, 2013
Organization [Abstract]
Organization	Note 1 - Organization The accompanying condensed consolidated financial statements of AmBase Corporation and its wholly-owned subsidiaries (the "Company") are unaudited and subject to year-end adjustments. All material intercompany transactions and balances have been eliminated. In the opinion of management, the interim financial statements reflect all adjustments, consisting only of normal recurring adjustments unless otherwise disclosed, necessary for a fair presentation of the Company's consolidated financial position, results of operations and cash flows. Results for interim periods are not necessarily indicative of results for the full year. The condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions, that it deems reasonable, that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from such estimates and assumptions. The unaudited interim condensed consolidated financial statements presented herein are condensed and should be read in conjunction with the Company's consolidated financial statements filed in its Annual Report on Form 10-K for the year ended December 31, 2012. The Company's assets currently consist primarily of cash and cash equivalents, investment securities, an indemnification asset, and real estate owned. The Company earns non-operating revenue consisting principally of investment earnings on investment securities and cash equivalents. The Company continues to evaluate a number of possible acquisitions and is engaged in the management of its assets and liabilities, including the contingent assets associated with its legal claims, as described in Notes 8 and 9. Discussions and negotiations are ongoing with respect to certain of these matters. From time to time, the Company and its subsidiaries may be named as a defendant in various lawsuits or proceedings. The Company intends to aggressively contest all litigation and contingencies, as well as pursue all sources for contributions to settlements.

Organization

3 Months Ended

Mar. 31, 2013

Note 1 - Organization

The accompanying condensed consolidated financial statements of AmBase Corporation and its wholly-owned subsidiaries (the "Company") are unaudited and subject to year-end adjustments. All material intercompany transactions and balances have been eliminated. In the opinion of management, the interim financial statements reflect all adjustments, consisting only of normal recurring adjustments unless otherwise disclosed, necessary for a fair presentation of the Company's consolidated financial position, results of operations and cash flows. Results for interim periods are not necessarily indicative of results for the full year. The condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions, that it deems reasonable, that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from such estimates and assumptions. The unaudited interim condensed consolidated financial statements presented herein are condensed and should be read in conjunction with the Company's consolidated financial statements filed in its Annual Report on Form 10-K for the year ended December 31, 2012.

The Company's assets currently consist primarily of cash and cash equivalents, investment securities, an indemnification asset, and real estate owned. The Company earns non-operating revenue consisting principally of investment earnings on investment securities and cash equivalents. The Company continues to evaluate a number of possible acquisitions and is engaged in the management of its assets and liabilities, including the contingent assets associated with its legal claims, as described in Notes 8 and 9. Discussions and negotiations are ongoing with respect to certain of these matters. From time to time, the Company and its subsidiaries may be named as a defendant in various lawsuits or proceedings. The Company intends to aggressively contest all litigation and contingencies, as well as pursue all sources for contributions to settlements.