Document and Entity Information - shares |
3 Months Ended | |
|---|---|---|
Apr. 30, 2019 |
Jun. 03, 2019 |
|
| Document And Entity Information [Abstract] | ||
| Document Type | 10-Q | |
| Amendment Flag | false | |
| Document Period End Date | Apr. 30, 2019 | |
| Document Fiscal Year Focus | 2020 | |
| Document Fiscal Period Focus | Q1 | |
| Trading Symbol | AMBA | |
| Entity Registrant Name | AMBARELLA INC | |
| Entity Central Index Key | 0001280263 | |
| Current Fiscal Year End Date | --01-31 | |
| Entity Filer Category | Large Accelerated Filer | |
| Entity Small Business | false | |
| Entity Emerging Growth Company | false | |
| Entity Common Stock, Shares Outstanding | 32,739,560 |