Junior Subordinated Debt - Additional Information (Detail) (USD $)			9 Months Ended		9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 TriCo Capital Trust I [Member]	Jul. 31, 2003 TriCo Capital Trust I [Member]	Sep. 30, 2014 TriCo Capital Trust II [Member]	Jun. 22, 2004 TriCo Capital Trust II [Member]
Class of Stock [Line Items]
Common stock shares issued	16,139,414	16,076,662		619		619
Common stock par value				$ 1,000		$ 1,000
Issuance of common stock, aggregate value				$ 619,000		$ 619,000
Issued Junior Subordinated Debenture to the trust				20,619,000		20,619,000
Offering of cumulative trust preferred securities				20,000		20,000
Cumulative trust preferred securities for cash in an aggregate amount				20,000,000		20,000,000
Redeem the trust preferred securities			Oct. 07, 2033		Jul. 23, 2034
LIBOR Rate, Description			Three-month LIBOR plus 3.05%		Three-month LIBOR plus 2.55%
Preferred securities redeemable interest rate			3.05%		2.55%
Company paid underwriting fees, per trust preferred security			$ 7.50		$ 2.50
Company paid underwriting fees aggregate			150,000		50,000
Net proceeds were used to finance the opening of new branches, services and technology			$ 19,850,000		$ 19,950,000
Debenture carried an interest rate			3.28%		2.78%