| Cover | Jun. 16, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Amendment Flag | true |
| Amendment Description | On June 21, 2022, Quantum Computing Inc. (the “Company”) filed a Current Report on Form 8-K (the “Initial Report”) to report the closing of the transactions contemplated by the agreement and plan of merger dated as of May 18, 2022 (the “Merger Agreement”), by and among the Company, Project Alpha Merger Sub I, Inc., a Delaware corporation, Project Alpha Merger Sub II, LLC, a Delaware limited liability company, QPhoton, Inc., a Delaware corporation (“QPhoton”), and Yuping Huang, the principal stockholder of QPhoton, whereby the Company agreed to acquire QPhoton through a series of merger transactions. On September 2, 2022, the Company filed an Amendment to Form 8-K (the “First Amendment”) that amended and supplemented the Initial Report to provide financial statements of QPhoton and the pro forma financial statements of the Company required by Item 9.01 of Form 8-K. The Company is filing this second amendment to the Initial Report (this “Second Amendment”) for the purpose of updating our Unaudited Pro Forma Combined Financial Information to (i) give effect, under ASC 805, to the acquisition accounting of the acquisition of QPhoton and (ii) disclose, pursuant to ASC 805, the date at which the stock price was determined. No other modifications to the Initial Report, as amended by the First Amendment, are being made by this Second Amendment. This Second Amendment should be read in connection with the Initial Report, which provides a more complete description of the Merger Agreement and transactions contemplated thereby, and the First Amendment. |
| Document Period End Date | Jun. 16, 2022 |
| Entity File Number | 001-40615 |
| Entity Registrant Name | QUANTUM COMPUTING INC. |
| Entity Central Index Key | 0001758009 |
| Entity Tax Identification Number | 82-4533053 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 215 Depot Court SE |
| Entity Address, Address Line Two | Suite 215 |
| Entity Address, City or Town | Leesburg |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 20175 |
| City Area Code | 703 |
| Local Phone Number | 436-2161 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $.0001 |
| Trading Symbol | QUBT |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
