| Cover | Feb. 02, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Feb. 2, 2021 |
| Entity Registrant Name | ITERIS, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-08762 |
| Entity Tax Identification Number | 95-2588496 |
| Entity Address, Address Line One | 1700 Carnegie Ave |
| Entity Address, Address Line Two | Suite 100 |
| Entity Address, City or Town | Santa Ana |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 92705 |
| City Area Code | 949 |
| Local Phone Number | 270-9400 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.10 par value |
| Trading Symbol | ITI |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Entity Central Index Key | 0000350868 |
