| Cover | Dec. 14, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Dec. 14, 2020 |
| Entity File Number | 001-34145 |
| Entity Registrant Name | Primoris Services Corporation |
| Entity Central Index Key | 0001361538 |
| Entity Tax Identification Number | 20-4743916 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 2300 N. Field Street |
| Entity Address, Address Line Two | Suite 1900 |
| Entity Address, City or Town | Dallas |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75201 |
| City Area Code | 214 |
| Local Phone Number | 740-5600 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.0001 par value |
| Trading Symbol | PRIM |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
