Junior Subordinated Debt - Summary of Terms and Recorded Balance of Subordinated Debenture (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Oct. 03, 2014
Subordinated Borrowing [Line Items]
Subordinated debenture, Face Value	$ 62,889,000
Subordinated debenture, Recorded Book Value	$ 56,617,000	$ 56,470,000
TriCo Capital Trust I [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Oct. 07, 2033
Subordinated debenture, Face Value	$ 20,619,000
Subordinated debenture, Coupon Rate	3.05%
Subordinated debenture, Current Coupon Rate	3.73%
Subordinated debenture, Recorded Book Value	$ 20,619,000	20,619,000
TriCo Capital Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Jul. 23, 2034
Subordinated debenture, Face Value	$ 20,619,000
Subordinated debenture, Coupon Rate	2.55%
Subordinated debenture, Current Coupon Rate	3.26%
Subordinated debenture, Recorded Book Value	$ 20,619,000	20,619,000
North Valley Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Apr. 24, 2033
Subordinated debenture, Face Value	$ 6,186,000		$ 6,186,000
Subordinated debenture, Current Coupon Rate	4.01%
Subordinated debenture, Recorded Book Value	$ 5,085,000	5,055,000	5,006,000
North Valley Trust III [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Apr. 24, 2034
Subordinated debenture, Face Value	$ 5,155,000		5,155,000
Subordinated debenture, Current Coupon Rate	3.51%
Subordinated debenture, Recorded Book Value	$ 3,995,000	3,966,000	3,918,000
North Valley Trust IV [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Mar. 15, 2036
Subordinated debenture, Face Value	$ 10,310,000		10,310,000
Subordinated debenture, Current Coupon Rate	2.18%
Subordinated debenture, Recorded Book Value	$ 6,299,000	$ 6,211,000	$ 6,063,000
LIBOR PLUS [Member] | TriCo Capital Trust I [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Coupon Rate	3.05%
LIBOR PLUS [Member] | TriCo Capital Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Coupon Rate	2.55%
LIBOR PLUS [Member] | North Valley Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Coupon Rate	3.25%
LIBOR PLUS [Member] | North Valley Trust III [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Coupon Rate	2.80%
LIBOR PLUS [Member] | North Valley Trust IV [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Coupon Rate	1.33%