| Document And Entity Information - USD ($) | Dec. 31, 2020 | Feb. 25, 2021 | Jun. 30, 2020 |
| Document Information [Line Items] | |||
| Entity, Registrant Name | Inphi Corporation | ||
| Current Fiscal Year End Date | --12-31 | ||
| Document, Fiscal Period Focus | FY | ||
| Document, Fiscal Year Focus | 2020 | ||
| Document, Type | 10-K/A | ||
| Document, Annual Report | true | ||
| Document, Period End Date | Dec. 31, 2020 | ||
| Document, Transition Report | false | ||
| Entity, File Number | 001-34942 | ||
| Entity, Incorporation, State or Country Code | DE | ||
| Entity, Tax Identification Number | 77-0557980 | ||
| Entity, Address, Address Line One | 110 Rio Robles | ||
| Entity, Address, City or Town | San Jose | ||
| Entity, Address, State or Province | CA | ||
| Entity, Address, Postal Zip Code | 95134 | ||
| City Area Code | 408 | ||
| Local Phone Number | 217-7300 | ||
| Title of 12(b) Security | Common Stock | ||
| Trading Symbol | IPHI | ||
| Security Exchange Name | NASDAQ | ||
| Entity, Well-known Seasoned Issuer | Yes | ||
| Entity, Voluntary Filers | No | ||
| Entity, Current Reporting Status | Yes | ||
| Entity, Interactive Data, Current | Yes | ||
| Entity, Filer Category | Large Accelerated Filer | ||
| Entity, Small Business | false | ||
| Entity, Emerging Growth Company | false | ||
| Entity, Shell Company | false | ||
| Entity, Public Float | $ 6,100,000,000 | ||
| Entity, Common Stock Shares, Outstanding | 53,672,718 | ||
| Amendment Description | This Amendment No. 1 to Form 10-K (this “Amendment”) amends the Annual Report on Form 10-K for the fiscal year ended December 31, 2020 (the “2020 Form 10-K”) originally filed on February 25, 2021 (the “Original Filing”) by Inphi Corporation, a Delaware corporation (“Inphi,” the “Company,” “we,” or “us”). We are filing this Amendment to present the information required by Part III of Form 10-K, and to update certain of the information included in the list of exhibits included in Item 15 and the Exhibit Index of this report. This Amendment hereby amends Part III, Items 10 through 14, and Part IV, Item 15(b) of the 2020 Form 10-K. In addition, as required by Rule 12b-15 under the Securities Exchange Act of 1934, as amended, new certifications by the registrant’s principal executive officer and principal financial officer are filed as exhibits to this Amendment. | ||
| Amendment Flag | true | ||
| Entity, Central Index Key | 0001160958 |
