| Document and Entity Information | Mar. 28, 2022 |
| Document And Entity Information [Line Items] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001824920 |
| Document Type | 8-K |
| Document Period End Date | Mar. 28, 2022 |
| Entity Registrant Name | IonQ, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-39694 |
| Entity Tax Identification Number | 85-2992192 |
| Entity Address, Address Line One | 4505 Campus Drive |
| Entity Address, City or Town | College Park |
| Entity Address, State or Province | MD |
| Entity Address, Postal Zip Code | 20740 |
| City Area Code | (301) |
| Local Phone Number | 298-7997 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Common Stock Par Value 0.0001 Per Share [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common Stock, par value $0.0001 per share |
| Trading Symbol | IONQ |
| Security Exchange Name | NYSE |
| Warrants Each Whole Warrant Exercisable For One Share Of Common Stock At An Exercise Price Of 11.50 Per Share [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Warrants, each whole warrant exercisable for one share of Common Stock at an exercise price of $11.50 per share |
| Trading Symbol | IONQ WS |
| Security Exchange Name | NYSE |
