8. Stock-based Compensation (Details Narrative)	6 Months Ended
	Jun. 30, 2021 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description of share-based compensation arrangement by share-based payment award	The Company has the Seelos Therapeutics, Inc. Amended and Restated 2012 Stock Long Term Incentive Plan (the “2012 Plan”), which provides for the issuance of incentive and non-incentive stock options, restricted and unrestricted stock awards, stock unit awards and stock appreciation rights. Options and restricted stock units granted generally vest over a period of one to four years and have a maximum term of ten years from the date of grant. As of June 30, 2021, an aggregate of 10,878,019 shares of common stock were authorized under the 2012 Plan, of which 1.6 million shares of common stock were available for future grants. Upon completion of the Merger, the Company assumed the Seelos Therapeutics, Inc. 2016 Equity Incentive Plan (the “2016 Plan”) and awards outstanding under the 2016 Plan became awards for common stock. Effective as of the Merger, no further awards may be issued under the 2016 Plan.
Share-based compensation arrangement by share-based payment award, number of shares authorized	10,878,019
Share-based compensation arrangement by share-based payment award, number of shares available for grant	1,600,000
Purchases under Employee Stock Purchase Plan percent of market price	85.00%
Stock Issued During Period, Shares, Employee Stock Ownership Plan	40,518
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description of share-based compensation arrangement by share-based payment award	During the six months ended June 30, 2021, the Company’s Board of Directors awarded a performance stock unit award to the Company’s Chief Executive Officer for 2,400,000 shares of common stock. Vesting of this award is subject to the Company achieving certain performance criteria established at the grant date and the individual fulfilling a service condition (continued employment). As of June 30, 2021, none of the performance conditions had been satisfied. The Company does not believe that the achievement of the performance criteria is probable at this time and therefore has not recognized any compensation expense during the six months ended June 30, 2021. Compensation expense will be recognized only once the performance condition is probable of being achieved and only for the cumulative amount related to the service condition that has been fulfilled.
Inducement Planof 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description of share-based compensation arrangement by share-based payment award	On July 28, 2019, the Compensation Committee of the Board of Directors (the “Compensation Committee”) of the Company adopted the Seelos Therapeutics, Inc. 2019 Inducement Plan (the “2019 Inducement Plan”), which became effective on August 12, 2019. The 2019 Inducement Plan provides for the grant of equity-based awards in the form of stock options, stock appreciation rights, restricted stock, unrestricted stock, stock units, including restricted stock units, performance units and cash awards, solely to prospective employees of the Company or an affiliate of the Company provided that certain criteria are met. Awards under the 2019 Inducement Plan may only be granted to an individual, as a material inducement to such individual to enter into employment with the Company, who (i) has not previously been an employee or director of the Company or (ii) is rehired following a bona fide period of non-employment with the Company. The maximum number of shares available for grant under the 2019 Inducement Plan is 1,000,000 shares of the Company’s common stock. The 2019 Inducement Plan is administered by the Compensation Committee and expires on August 12, 2029.
Incentive Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period	304,621
Weighted-average exercise price per share granted in period | $ / shares	$ 4.20
Term of option grant	10 years
Vesting percentage on the first anniversary	25.00%
Non Qualified Stock Options To Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period	1,755,379
Weighted-average exercise price per share granted in period | $ / shares	$ 4.20
Term of option grant	10 years
Vesting percentage on the first anniversary	25.00%
Non Qualified Stock Options To Non Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in period	64,000
Weighted-average exercise price per share granted in period | $ / shares	$ 1.35
Term of option grant	10 years
Vesting period	12 months