The Company and Basis of Presentation and Going Concern	6 Months Ended
Jun. 30, 2017
The Company and Basis of Presentation and Going Concern [Abstract]
The Company and Basis of Presentation and Going Concern	Note 1 – The Company and Basis of Presentation and Going Concern The accompanying condensed consolidated financial statements of AmBase Corporation and subsidiaries ("AmBase" or the "Company") are unaudited and subject to year-end adjustments. All material intercompany transactions and balances have been eliminated. In the opinion of management, these 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 8 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, 2016. The Company's assets currently consist primarily of cash and cash equivalents, an equity investment in a real estate development property and real estate owned. The Company owns an equity interest in a real estate development property through a joint venture agreement to purchase and develop real property located at 105 through 111 West 57^th Street in New York (the "111 West 57^th Property"). As further discussed herein below and in Note 4, Note 9 and Note 11, the Company is engaged in material disputes and litigation with the sponsor of the joint venture and a mezzanine lender to the joint venture. The Company is otherwise engaged in the management of its assets and liabilities. In April 2016, AmBase initiated a litigation in the New York State Supreme Court for New York County (the "NY Court"), Index No. 652301/2016, ("AmBase v. 111 West 57^th Sponsor LLC, et al.") (the "111 West 57^th Action"). The defendants in that litigation are 111 West 57th Sponsor LLC, 111 West 57th JDS LLC, PMG West 57th Street LLC, 111 West 57th Control LLC, 111 West 57th Developer LLC, Elliot Joseph, 111 West 57^th KM Equity LLC, 111 West 57^th KM Group LLC, Kevin Maloney, Matthew Phillips, Michael Stern, Ned White and Franklin R. Kaiman (collectively, "Defendants") and nominal defendant 111 West 57th Partners LLC. AmBase alleges in that action, among other claims, that the Defendants engaged in an unlawful scheme to dilute AmBase's equity interest in the joint real estate venture 111 West 57^th Partners, to develop the 111 West 57^th Street Property and to keep for themselves certain financing opportunities in breach of Defendants' contractual and fiduciary duties. The complaint also alleges that defendants have failed to honor the exercise of AmBase's contractual "equity put right" as set forth in the JV Agreement (the "Equity Put Right"). AmBase is seeking compensatory damages, as well as punitive damages, indemnification and equitable relief including a declaration of the parties' rights, an accounting and a constructive trust over distributions received by the Defendants. The complaint in this action has been filed, a motion to dismiss is pending and discovery is ongoing. The Company has also demanded from the Sponsors access to the books and records for the 111 West 57^th Property which the Sponsors have refused, claiming they have provided all books and records as required. For additional information, see Note 4, Note 9 and Note 11. For additional information with regard to, among other items, recent developments concerning the Company's investment in the 111 West 57^th Property, information concerning the junior mezzanine lender declaration of an event of default and its proposal to take control of the collateral pledged by the junior mezzanine borrower and therefore, the Company's entire interest in the 111 West 57th Street Property, the Company's request for injunctive relief, and the NY Court's issuance of a temporary restraining order pending a preliminary injunction hearing, see Note 4, Note 9, and Note 11. A fundamental principle of the preparation of financial statements in accordance with GAAP is the assumption that an entity will continue in existence as a going concern, which contemplates continuity of operations and the realization of assets and settlement of liabilities occurring in the ordinary course of business. In accordance with this requirement, the Company has prepared its accompanying condensed consolidated financial statements assuming the Company will continue as a going concern. The Company has incurred operating losses and used cash for operating activities for the past several years. The Company has also made significant investments in the 111 West 57th Street Property since 2013. The Company has continued to keep operating expenses at a reduced level; however, there can be no assurance that the Company's current level of operating expenses will not increase or that other uses of cash will not be necessary. The Company believes that based on its current level of operating expenses, its currently available cash and financial resources together with the borrowings and line of credit from Mr. Richard A. Bianco, the Company's Chairman, President and Chief Executive Officer ("Mr. R. A. Bianco") as further discussed in Note 10 herein, may not be sufficient to cover operating cash needs through the twelve month period from the financial statement reporting date. Based on the above factors, management determined there is substantial doubt about the Company's ability to continue as a going concern within one year after the date that the financial statements are issued. The accompanying condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern. The financial statements do not include adjustments to the carrying value of assets and liabilities which might be necessary should the Company not continue in operation. Over the next several months, the Company will seek to manage its current level of cash and cash equivalents, through various ways, including but not limited to, reducing operating expenses, possible asset sales and/or long term borrowings, although this cannot be assured. In order to continue on a long-term basis, the Company must raise additional capital through the sale of assets or long term borrowings. There can be no assurance that the Company will be able to attain such financing at terms acceptable to the Company, if at all. With respect to its current disputes and litigation relating to its interest in the 111 West 57th Property, the Company will continue to pursue all available legal courses of action as well as considering other possible economic strategies, including the possible sale of the Company's investment interest in the 111 West 57th Property. The Company is negotiating with all potential parties to protect the Company's interests. Additionally, the Company is pursuing alternative financial resources to help finance current and future litigation in the courts to protect the Company's investment value, including negotiating possible contingency arrangements with legal counsel and/or raising capital for the Company to pursue its legal rights.

Note 1 – The Company and Basis of Presentation and Going Concern

The accompanying condensed consolidated financial statements of AmBase Corporation and subsidiaries ("AmBase" or the "Company") are unaudited and subject to year-end adjustments. All material intercompany transactions and balances have been eliminated. In the opinion of management, these 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 8 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, 2016.

The Company's assets currently consist primarily of cash and cash equivalents, an equity investment in a real estate development property and real estate owned. The Company owns an equity interest in a real estate development property through a joint venture agreement to purchase and develop real property located at 105 through 111 West 57^th Street in New York (the "111 West 57^th Property"). As further discussed herein below and in Note 4, Note 9 and Note 11, the Company is engaged in material disputes and litigation with the sponsor of the joint venture and a mezzanine lender to the joint venture. The Company is otherwise engaged in the management of its assets and liabilities.

In April 2016, AmBase initiated a litigation in the New York State Supreme Court for New York County (the "NY Court"), Index No. 652301/2016, ("AmBase v. 111 West 57^th Sponsor LLC, et al.") (the "111 West 57^th Action"). The defendants in that litigation are 111 West 57th Sponsor LLC, 111 West 57th JDS LLC, PMG West 57th Street LLC, 111 West 57th Control LLC, 111 West 57th Developer LLC, Elliot Joseph, 111 West 57^th KM Equity LLC, 111 West 57^th KM Group LLC, Kevin Maloney, Matthew Phillips, Michael Stern, Ned White and Franklin R. Kaiman (collectively, "Defendants") and nominal defendant 111 West 57th Partners LLC. AmBase alleges in that action, among other claims, that the Defendants engaged in an unlawful scheme to dilute AmBase's equity interest in the joint real estate venture 111 West 57^th Partners, to develop the 111 West 57^th Street Property and to keep for themselves certain financing opportunities in breach of Defendants' contractual and fiduciary duties. The complaint also alleges that defendants have failed to honor the exercise of AmBase's contractual "equity put right" as set forth in the JV Agreement (the "Equity Put Right"). AmBase is seeking compensatory damages, as well as punitive damages, indemnification and equitable relief including a declaration of the parties' rights, an accounting and a constructive trust over distributions received by the Defendants. The complaint in this action has been filed, a motion to dismiss is pending and discovery is ongoing. The Company has also demanded from the Sponsors access to the books and records for the 111 West 57^th Property which the Sponsors have refused, claiming they have provided all books and records as required. For additional information, see Note 4, Note 9 and Note 11.

For additional information with regard to, among other items, recent developments concerning the Company's investment in the 111 West 57^th Property, information concerning the junior mezzanine lender declaration of an event of default and its proposal to take control of the collateral pledged by the junior mezzanine borrower and therefore, the Company's entire interest in the 111 West 57th Street Property, the Company's request for injunctive relief, and the NY Court's issuance of a temporary restraining order pending a preliminary injunction hearing, see Note 4, Note 9, and Note 11.

A fundamental principle of the preparation of financial statements in accordance with GAAP is the assumption that an entity will continue in existence as a going concern, which contemplates continuity of operations and the realization of assets and settlement of liabilities occurring in the ordinary course of business. In accordance with this requirement, the Company has prepared its accompanying condensed consolidated financial statements assuming the Company will continue as a going concern.

The Company has incurred operating losses and used cash for operating activities for the past several years. The Company has also made significant investments in the 111 West 57th Street Property since 2013. The Company has continued to keep operating expenses at a reduced level; however, there can be no assurance that the Company's current level of operating expenses will not increase or that other uses of cash will not be necessary. The Company believes that based on its current level of operating expenses, its currently available cash and financial resources together with the borrowings and line of credit from Mr. Richard A. Bianco, the Company's Chairman, President and Chief Executive Officer ("Mr. R. A. Bianco") as further discussed in Note 10 herein, may not be sufficient to cover operating cash needs through the twelve month period from the financial statement reporting date. Based on the above factors, management determined there is substantial doubt about the Company's ability to continue as a going concern within one year after the date that the financial statements are issued. The accompanying condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern. The financial statements do not include adjustments to the carrying value of assets and liabilities which might be necessary should the Company not continue in operation.

Over the next several months, the Company will seek to manage its current level of cash and cash equivalents, through various ways, including but not limited to, reducing operating expenses, possible asset sales and/or long term borrowings, although this cannot be assured. In order to continue on a long-term basis, the Company must raise additional capital through the sale of assets or long term borrowings. There can be no assurance that the Company will be able to attain such financing at terms acceptable to the Company, if at all.

With respect to its current disputes and litigation relating to its interest in the 111 West 57th Property, the Company will continue to pursue all available legal courses of action as well as considering other possible economic strategies, including the possible sale of the Company's investment interest in the 111 West 57th Property. The Company is negotiating with all potential parties to protect the Company's interests. Additionally, the Company is pursuing alternative financial resources to help finance current and future litigation in the courts to protect the Company's investment value, including negotiating possible contingency arrangements with legal counsel and/or raising capital for the Company to pursue its legal rights.