| Component: (Network and Table) | |
|---|---|
| Network | 100440 - Disclosure - Property and Equipment, Net - Schedule of Property and Equipment (Detail) (http://www.ambarella.com/20170131/taxonomy/role/DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentDetail) |
| Table | Schedule Of Property Plant And Equipment [Table] |
| Reporting Entity [Axis] | 0001280263 (http://www.sec.gov/CIK) |
| Property Plant And Equipment [Line Items] | Period [Axis] | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
2017-01-31 | 2016-01-31 | |||||||||||
| Property, Plant and Equipment, Type | Property, Plant and Equipment, Type | |||||||||||
| Computer equipment and software [Member] | Machinery and equipment [Member] | Furniture and fixtures [Member] | Leasehold improvements [Member] | Construction in progress [Member] | Property, Plant and Equipment, Type | Computer equipment and software [Member] | Machinery and equipment [Member] | Furniture and fixtures [Member] | Leasehold improvements [Member] | Construction in progress [Member] | Property, Plant and Equipment, Type | |
Property and equipment, gross | ||||||||||||
Less: accumulated depreciation and amortization | ( | ( | ||||||||||
Total property and equipment, net | 4,988,000 | 3,448,000 | ||||||||||