Merger	12 Months Ended
Dec. 31, 2018
Business Combinations [Abstract]
Merger	2. MERGER On January 24, 2019, the Company completed its business combination with STI in accordance with the terms of the Agreement and Plan of Merger and Reorganization, dated as of July 30, 2018 (the "Merger Agreement"), by and among the Company, Arch Merger Sub, Inc. ("Merger Sub"), and STI, as amended by Amendment No. 1 thereto made and entered into as of October 16, 2018 (the "First Amendment"), Amendment No. 2 thereto made and entered into as of December 14, 2018 (the "Second Amendment") and Amendment No. 3 thereto made and entered into as of January 16, 2019 (the "Third Amendment" and the Merger Agreement, as amended by the First Amendment, Second Amendment and Third Amendment, the "Amended Merger Agreement"), pursuant to which Merger Sub merged with and into STI, with STI surviving as the Company's wholly-owned subsidiary. On January 23, 2019, in connection with, and prior to the completion of, the Merger, the Company effected a reverse stock split of its common stock, par value $0.001 per share, at a ratio of 1-for-30 (the "Reverse Stock Split"), and on January 24, 2019, immediately after completion of the Merger, the Company changed its name to "Seelos Therapeutics, Inc." Following the completion of the Merger, the business conducted by the Company became primarily the business conducted by STI, which is a clinical-stage biopharmaceutical company focused on the development and advancement of novel therapeutics to address unmet medical needs for the benefit of patients with central nervous system disorders. Under the terms of the Amended Merger Agreement, the Company issued shares of its common stock to the stockholders of STI at an exchange rate of 0.7704 shares of its common stock, after taking into account the Reverse Stock Split, for each share of STI's common stock outstanding immediately prior to the Merger. The exchange rate was determined through arms'-length negotiations between the Company and the STI. The Company also assumed all of the stock options outstanding under STI's 2016 Equity Incentive Plan (the "2016 Plan") with such stock options henceforth representing the right to purchase a number of shares of the Company's common stock equal to 0.7704 multiplied by the number of shares of STI's common stock previously represented by such options. Immediately after the Merger, there were approximately 6,221,822 shares of the Company's common stock outstanding, subject to rounding up any fractional shares as a result of the Reverse Stock Split as further described below. Immediately after the Merger, the former stockholders, optionholders and noteholders of STI owned, or held rights to acquire, approximately 84.85% of the fully-diluted shares of the Company's common stock, which for these purposes is defined as the outstanding shares of common stock, plus restricted stock units and "in the money" options and warrants to purchase shares of Common Stock, assuming that all of its "in the money" options and warrants outstanding immediately prior to the Merger were exercised on a cashless basis immediately prior to the closing of the Merger (the "Fully-Diluted Capitalization"), with its stockholders, optionholders, restricted stock unit holders and warrantholders immediately prior to the Merger owning, or holding rights to acquire, approximately 15.15% of the Fully-Diluted Capitalization. The shares of common stock issued to the former stockholders of STI were registered with the SEC. The shares of the Company's common stock listed on the Nasdaq Capital Market, previously trading through the close of business on January 23, 2019 under the ticker symbol "APRI," commenced trading on the Nasdaq Capital Market, on a post-Reverse Stock Split adjusted basis, under the ticker symbol "SEEL" on January 24, 2019. Contingent Value Rights Agreement Upon the closing of the Merger, the Company, STI, Richard Pascoe, as representative of the Company's stockholders, and a rights agent entered into the Contingent Value Rights Agreement (the "CVR Agreement"). Pursuant to the CVR Agreement, Company stockholders will receive one CVR for each share of the Company's common stock held of record immediately prior to the closing of the Merger. Each CVR will represent the right to receive payments based on the Company's Vitaros assets. In particular, CVR holders will be entitled to receive 90% of any cash payments (or the fair market value of any non-cash payments) exceeding $500,000 received, during a period of ten years from the closing of the Merger, based on the sale or out-licensing of the Vitaros assets, including any contingent payments, less reasonable transaction expenses. The Company is entitled to retain the first $500,000 and 10% of any contingent payments. In order to be eligible for the CVR, a Company stockholder must have been a holder of record at the close of business immediately prior to the closing of the Merger. The Company agreed to use commercially reasonable efforts to out-license or sell the Vitaros assets for a period of three years following the closing of the Merger. The CVRs are not be transferable, except in limited circumstances and will not be registered with the SEC. Richard Pascoe, the Company's former President and CEO, was appointed to serve as the representative of the CVR holders' interests under the CVR Agreement.

Merger

12 Months Ended

Dec. 31, 2018

2. MERGER

On January 24, 2019, the Company completed its business combination with STI in accordance with the terms of the Agreement and Plan of Merger and Reorganization, dated as of July 30, 2018 (the "Merger Agreement"), by and among the Company, Arch Merger Sub, Inc. ("Merger Sub"), and STI, as amended by Amendment No. 1 thereto made and entered into as of October 16, 2018 (the "First Amendment"), Amendment No. 2 thereto made and entered into as of December 14, 2018 (the "Second Amendment") and Amendment No. 3 thereto made and entered into as of January 16, 2019 (the "Third Amendment" and the Merger Agreement, as amended by the First Amendment, Second Amendment and Third Amendment, the "Amended Merger Agreement"), pursuant to which Merger Sub merged with and into STI, with STI surviving as the Company's wholly-owned subsidiary. On January 23, 2019, in connection with, and prior to the completion of, the Merger, the Company effected a reverse stock split of its common stock, par value $0.001 per share, at a ratio of 1-for-30 (the "Reverse Stock Split"), and on January 24, 2019, immediately after completion of the Merger, the Company changed its name to "Seelos Therapeutics, Inc." Following the completion of the Merger, the business conducted by the Company became primarily the business conducted by STI, which is a clinical-stage biopharmaceutical company focused on the development and advancement of novel therapeutics to address unmet medical needs for the benefit of patients with central nervous system disorders.

Under the terms of the Amended Merger Agreement, the Company issued shares of its common stock to the stockholders of STI at an exchange rate of 0.7704 shares of its common stock, after taking into account the Reverse Stock Split, for each share of STI's common stock outstanding immediately prior to the Merger. The exchange rate was determined through arms'-length negotiations between the Company and the STI. The Company also assumed all of the stock options outstanding under STI's 2016 Equity Incentive Plan (the "2016 Plan") with such stock options henceforth representing the right to purchase a number of shares of the Company's common stock equal to 0.7704 multiplied by the number of shares of STI's common stock previously represented by such options.

Immediately after the Merger, there were approximately 6,221,822 shares of the Company's common stock outstanding, subject to rounding up any fractional shares as a result of the Reverse Stock Split as further described below. Immediately after the Merger, the former stockholders, optionholders and noteholders of STI owned, or held rights to acquire, approximately 84.85% of the fully-diluted shares of the Company's common stock, which for these purposes is defined as the outstanding shares of common stock, plus restricted stock units and "in the money" options and warrants to purchase shares of Common Stock, assuming that all of its "in the money" options and warrants outstanding immediately prior to the Merger were exercised on a cashless basis immediately prior to the closing of the Merger (the "Fully-Diluted Capitalization"), with its stockholders, optionholders, restricted stock unit holders and warrantholders immediately prior to the Merger owning, or holding rights to acquire, approximately 15.15% of the Fully-Diluted Capitalization.

The shares of common stock issued to the former stockholders of STI were registered with the SEC.

The shares of the Company's common stock listed on the Nasdaq Capital Market, previously trading through the close of business on January 23, 2019 under the ticker symbol "APRI," commenced trading on the Nasdaq Capital Market, on a post-Reverse Stock Split adjusted basis, under the ticker symbol "SEEL" on January 24, 2019.

Contingent Value Rights Agreement

Upon the closing of the Merger, the Company, STI, Richard Pascoe, as representative of the Company's stockholders, and a rights agent entered into the Contingent Value Rights Agreement (the "CVR Agreement"). Pursuant to the CVR Agreement, Company stockholders will receive one CVR for each share of the Company's common stock held of record immediately prior to the closing of the Merger. Each CVR will represent the right to receive payments based on the Company's Vitaros assets. In particular, CVR holders will be entitled to receive 90% of any cash payments (or the fair market value of any non-cash payments) exceeding $500,000 received, during a period of ten years from the closing of the Merger, based on the sale or out-licensing of the Vitaros assets, including any contingent payments, less reasonable transaction expenses. The Company is entitled to retain the first $500,000 and 10% of any contingent payments. In order to be eligible for the CVR, a Company stockholder must have been a holder of record at the close of business immediately prior to the closing of the Merger. The Company agreed to use commercially reasonable efforts to out-license or sell the Vitaros assets for a period of three years following the closing of the Merger.

The CVRs are not be transferable, except in limited circumstances and will not be registered with the SEC. Richard Pascoe, the Company's former President and CEO, was appointed to serve as the representative of the CVR holders' interests under the CVR Agreement.