| Document and Entity Information | May 04, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | May 4, 2020 |
| Entity File Number | 001-12257 |
| Entity Registrant Name | MERCURY GENERAL CORPORATION |
| Entity Incorporation, State or Country Code | CA |
| Entity Tax Identification Number | 95-2211612 |
| Entity Address, Address Line One | 4484 Wilshire Boulevard |
| Entity Address, City or Town | Los Angeles |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 90010 |
| City Area Code | 323 |
| Local Phone Number | 937-1060 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000064996 |
| Amendment Flag | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | MCY |
| Security Exchange Name | NYSE |
