| Component: (Network and Table) | |
|---|---|
| Network | 2408404 - Disclosure - Convertible Preferred Stock and Stockholders' Deficit - Schedule of Outstanding Warrants (Details) (http://www.obalon.com/role/ConvertiblePreferredStockAndStockholdersDeficitScheduleOfOutstandingWarrantsDetails) |
| Table | Class Of Warrant Or Right [Table] |
| Reporting Entity [Axis] | 0001427570 (http://www.sec.gov/CIK) |
| Class of Stock | Series C Convertible Preferred Stock |
| Class of Warrant or Right | Feb 24, 2012 Warrant Issuance |
| Class Of Warrant Or Right [Line Items] | Period [Axis] |
|---|---|
2016-12-31 | |
Shares | |
Weighted-average exercise price (in dollars per share) |