Cover Page - shares	6 Months Ended
	Jun. 30, 2021	Aug. 06, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	000-10661
Entity Incorporation, State or Country Code	CA
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
Title of 12(b) Security	Common Stock
Trading Symbol	TCBK
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		29,711,934
Entity Registrant Name	TriCo Bancshares
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000356171