Junior Subordinated Debt - Additional Information (Detail) (USD $)	3 Months Ended	0 Months Ended
	Mar. 31, 2015	Oct. 03, 2014	Dec. 31, 2014	Jul. 31, 2003	Jun. 22, 2004
Class of Stock [Line Items]
Common stock shares issued	22,740,503		22,714,964
Subordinated debenture, Face Value	62,889,000
Subordinated debenture, recorded fair value	56,320,000		56,272,000
North Valley Bancorp [Member]
Class of Stock [Line Items]
Acquisition, completion date	Oct. 03, 2014
North Valley Trust II [Member]
Class of Stock [Line Items]
Subordinated debenture, Face Value	6,186,000	6,186,000
Acquisition of common stock interests		186,000
Subordinated debenture, recorded fair value	5,025,000	5,006,000
North Valley Trust III [Member]
Class of Stock [Line Items]
Subordinated debenture, Face Value	5,155,000	5,155,000
Acquisition of common stock interests		155,000
Subordinated debenture, recorded fair value	3,936,000	3,918,000
North Valley Trust IV [Member]
Class of Stock [Line Items]
Subordinated debenture, Face Value	10,310,000	10,310,000
Acquisition of common stock interests		310,000
Subordinated debenture, recorded fair value	6,121,000	6,063,000
TriCo Capital Trust I [Member]
Class of Stock [Line Items]
Common stock shares issued				619
Common stock par value				$ 1,000
Issuance of common stock, aggregate value				619,000
Issued Junior Subordinated Debenture to the trust				20,619,000
Offering of cumulative trust preferred securities				20,000
Cumulative trust preferred securities for cash in an aggregate amount				20,000,000
Redeem the trust preferred securities	Oct. 07, 2033
LIBOR Rate, Description	Three-month LIBOR plus 3.05%
Preferred securities redeemable interest rate	3.05%
Company paid underwriting fees, per trust preferred security	7.50
Company paid underwriting fees aggregate	150,000
Net proceeds were used to finance the opening of new branches, services and technology	19,850,000
TriCo Capital Trust II [Member]
Class of Stock [Line Items]
Common stock shares issued					619
Common stock par value					$ 1,000
Issuance of common stock, aggregate value					619,000
Issued Junior Subordinated Debenture to the trust					20,619,000
Offering of cumulative trust preferred securities					20,000
Cumulative trust preferred securities for cash in an aggregate amount					20,000,000
Redeem the trust preferred securities	Jul. 23, 2034
LIBOR Rate, Description	Three-month LIBOR plus 2.55%
Preferred securities redeemable interest rate	2.55%
Company paid underwriting fees, per trust preferred security	2.50
Company paid underwriting fees aggregate	50,000
Net proceeds were used to finance the opening of new branches, services and technology	19,950,000