| Document and Entity Information | Mar. 06, 2022 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001391127 |
| Document Type | 8-K |
| Document Period End Date | Mar. 6, 2022 |
| Entity Registrant Name | LIMELIGHT NETWORKS, INC. |
| Entity File Number | 001-33508 |
| Entity Incorporation State Country Code | DE |
| Entity Tax Identification Number | 20-1677033 |
| Entity Address, Address Line One | 2222 West 14th Street |
| Entity Address, City or Town | Tempe |
| Entity Address, State or Province | AZ |
| Entity Address, Postal Zip Code | 85281 |
| City Area Code | (602) |
| Local Phone Number | 850-5000 |
| Written Communications | false |
| Soliciting Material | true |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, $0.001 per share |
| Trading Symbol | LLNW |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
