Basis of Presentation, Liquidity and Risks and Uncertainties	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation, Liquidity and Risks and Uncertainties	Basis of Presentation, Liquidity and Risks and Uncertainties Basis of Presentation The accompanying unaudited condensed consolidated financial statements of Inovio have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) as contained in the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") for interim financial information and with instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. The condensed consolidated balance sheet as of June 30, 2021, the condensed consolidated statements of operations, the condensed consolidated statements of comprehensive loss and the condensed consolidated statements of stockholders' equity for the three and six months ended June 30, 2021 and 2020 and the condensed consolidated statements of cash flows for the six months ended June 30, 2021 and 2020 are unaudited, but include all adjustments (consisting of normal recurring adjustments) that the Company considers necessary for a fair presentation of the financial position, results of operations, cash flows and changes in stockholders' equity for the periods presented. The results of operations for the three and six months ended June 30, 2021 shown herein are not necessarily indicative of the results that may be expected for the year ending December 31, 2021, or for any other period. These unaudited financial statements, and notes thereto, should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2020, included in the Company's Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (“SEC”) on March 1, 2021. The balance sheet at December 31, 2020 has been derived from the audited financial statements at that date, but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In June 2020, the Company formed a wholly-owned subsidiary, Inovio Asia LLC, under the laws of South Korea, through which the Company intends to advance its corporate development projects and other functions in South Korea and other Asian countries. These unaudited condensed consolidated financial statements include the accounts of Inovio Pharmaceuticals, Inc. and its subsidiaries. As of June 30, 2021, the Company consolidated its wholly-owned subsidiary Inovio Asia LLC. On December 31, 2020, former wholly-owned subsidiaries Genetronics, Inc. and VGX Pharmaceuticals Inc. and former majority-owned subsidiary VGX Animal Health, Inc. were merged into Inovio Pharmaceuticals, Inc. All intercompany accounts and transactions were eliminated upon consolidation. As of June 1, 2020, the Company deconsolidated its former subsidiary Geneos Therapeutics, Inc. ("Geneos"), as the Company no longer held a controlling financial interest. Refer to Footnote 17 for further discussion. Liquidity The Company incurred a net loss attributable to common stockholders of $82.1 million and $136.5 million for the three and six months ended June 30, 2021, respectively. The Company had working capital of $490.7 million and an accumulated deficit of $1.0 billion as of June 30, 2021. The Company has incurred losses in each year since its inception and expects to continue to incur significant expenses and operating losses for the foreseeable future in connection with the research and preclinical and clinical development of its product candidates. The Company’s cash, cash equivalents and short-term investments of $443.7 million as of June 30, 2021 are sufficient to support the Company's operations for a period of at least 12 months from the date of issuance of these financial statements. In order to continue to fund future research and development activities, the Company will need to seek additional capital. This may occur through strategic alliance and licensing arrangements, grant agreements and/or future public or private debt or equity financings including use of potential future At-the-Market Equity Offering Sales Agreements (“Sales Agreements”). The Company has a history of conducting debt and equity financings, including the receipt of net proceeds of $162.1 million from a January 2021 underwritten public offering and net proceeds of $454.5 million under past Sales Agreements for the year ended December 31, 2020. However, sufficient funding may not be available in the future, or if available, may be on terms that significantly dilute or otherwise adversely affect the rights of existing stockholders. If adequate funds are not available, the Company may need to delay, reduce the scope of or put on hold one or more of its clinical and/or preclinical programs. The Company’s ability to continue its operations is dependent upon its ability to obtain additional capital in the future and achieve profitable operations. The Company expects to continue to rely on outside sources of financing to meet its capital needs and the Company may never achieve positive cash flow. These condensed consolidated financial statements do not include any adjustments to the specific amounts and classifications of assets and liabilities, which might be necessary should Inovio be unable to continue as a going concern. The Company's condensed consolidated financial statements as of and for the three and six months ended June 30, 2021 have been prepared on a going concern basis, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business for the foreseeable future. The Company has evaluated subsequent events after the balance sheet date through the date it issued these condensed consolidated financial statements. The Company is and, from time to time, may in the future be subject to various legal proceedings and claims arising in the ordinary course of business. The Company assesses contingencies to determine the degree of probability and range of possible loss for potential accrual in its consolidated financial statements. An estimated loss contingency is accrued in the consolidated financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Legal proceedings, including litigation, government investigations and enforcement actions, could result in material costs, occupy significant management resources and entail civil and criminal penalties, even if the Company ultimately prevails. Any of the foregoing consequences could result in serious harm to the Company’s business, results of operations and financial condition. Risks and Uncertainties The global pandemic resulting from COVID-19, caused by a novel strain of coronavirus, SARS-CoV-2, has caused national and global economic and financial market disruptions. The impact of this pandemic has been and will likely continue to be extensive in many aspects of society, which has resulted in and will continue to cause significant disruptions to the global economy, as well as businesses and capital markets around the world. The Company continues to closely monitor the impact of the COVID-19 pandemic on its employees, collaborators and service providers. The extent to which the pandemic will continue to impact the Company's business and operations will depend on future developments, including travel restrictions and social distancing in the United States and other countries, and the effectiveness of actions taken in the United States and other countries to contain and treat the disease, including mass vaccination efforts, that are highly uncertain as of the date the Company is issuing these financial statements.