Document and Entity Information
6 Months Ended
Jul. 31, 2014
Document And Entity Information [Abstract]  
Document Type 10-Q
Amendment Flag false
Document Period End Date Jul. 31, 2014
Document Fiscal Year Focus 2015
Document Fiscal Period Focus Q2
Trading Symbol AMBA
Entity Registrant Name AMBARELLA INC
Entity Central Index Key 0001280263
Current Fiscal Year End Date --01-31
Entity Filer Category Accelerated Filer
Entity Common Stock, Shares Outstanding 29,695,783