| Cover | Oct. 26, 2021 | Apr. 28, 2021 |
| Cover [Abstract] | ||
| Document Type | 8-K | |
| Document Period End Date | Oct. 26, 2021 | |
| Entity Registrant Name | TriCo Bancshares | |
| Entity Incorporation, State or Country Code | CA | |
| Entity File Number | 0-10661 | |
| Entity Tax Identification Number | 94-2792841 | |
| Entity Address, Address Line One | 63 Constitution Drive | |
| Entity Address, City or Town | Chico, | |
| Entity Address, State or Province | CA | |
| Entity Address, Postal Zip Code | 95973 | |
| City Area Code | 530 | |
| Local Phone Number | 898-0300 | |
| Written Communications | false | |
| Soliciting Material | false | |
| Pre-commencement Tender Offer | false | |
| Pre-commencement Issuer Tender Offer | false | |
| Title of 12(b) Security | Common Stock, no par value | |
| Trading Symbol | TCBK | |
| Security Exchange Name | NASDAQ | |
| Entity Emerging Growth Company | false | |
| Amendment Flag | false | |
| Entity Central Index Key | 0000356171 |
