Junior Subordinated Debt (Details) (USD $)			9 Months Ended		9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 TriCo Capital Trust I [Member]	Jul. 31, 2003 TriCo Capital Trust I [Member]	Sep. 30, 2012 TriCo Capital Trust II [Member]	Jun. 22, 2004 TriCo Capital Trust II [Member]
Junior Subordinated Debt (Textual) [Abstract]
Common stock shares issued	15,992,893	15,978,958	619		619
Common stock par value			$ 1,000		$ 1,000
Issuance of common stock, aggregate value			$ 619,000		$ 619,000
The Company issued a 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
Preferred securities redeemable interest rate			3.05%		2.55%
Redeem the trust preferred securities			Oct. 07, 2033		Jul. 24, 2034
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 opening of new branches, services and technology			19,850,000		19,950,000
Junior subordinated debentures issued			$ 20,619,000		$ 20,619,000
Interest rates on junior subordinated debentures			3.505%		3.00%