| Document and Entity Information | Aug. 16, 2021 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001801169 |
| Document Type | 8-K |
| Document Period End Date | Aug. 16, 2021 |
| Entity Registrant Name | Opendoor Technologies Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-39253 |
| Entity Tax Identification Number | 98-1515020 |
| Entity Address, Address Line One | 410 N. Scottsdale Road |
| Entity Address, Address Line Two | Suite 1600 |
| Entity Address, City or Town | Tempe |
| Entity Address, State or Province | AZ |
| Entity Address, Postal Zip Code | 85281 |
| City Area Code | (415) |
| Local Phone Number | 896-6737 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, par value $0.0001 per share |
| Trading Symbol | OPEN |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
