Borrowings - Summary of Terms and Recorded Balance of Subordinated Debenture (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 101,080	$ 101,040
Subordinated Debt
Subordinated Borrowing [Line Items]
Face Value	98,889
TriCo Cap Trust I
Subordinated Borrowing [Line Items]
Recorded Book Value	20,619	20,619
TriCo Cap Trust I | Subordinated Debt
Subordinated Borrowing [Line Items]
Face Value	$ 20,619
Current Coupon Rate	8.62%
TriCo Cap Trust II
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 20,619	20,619
TriCo Cap Trust II | Subordinated Debt
Subordinated Borrowing [Line Items]
Face Value	$ 20,619
Current Coupon Rate	8.16%
North Valley Trust II
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 5,576	5,503
North Valley Trust II | Subordinated Debt
Subordinated Borrowing [Line Items]
Face Value	$ 6,186
Current Coupon Rate	8.88%
North Valley Trust III
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 4,449	4,383
North Valley Trust III | Subordinated Debt
Subordinated Borrowing [Line Items]
Face Value	$ 5,155
Current Coupon Rate	8.41%
North Valley Trust IV
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 7,557	7,393
North Valley Trust IV | Subordinated Debt
Subordinated Borrowing [Line Items]
Face Value	$ 10,310
Current Coupon Rate	7.00%
VRB Subordinated - 6%
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 17,046	17,187
VRB Subordinated - 6% | Subordinated Debt
Subordinated Borrowing [Line Items]
Interest rate	6.00%
Face Value	$ 16,000
Current Coupon Rate	6.00%
VRB Subordinated - 5%
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 25,214	$ 25,336
VRB Subordinated - 5% | Subordinated Debt
Subordinated Borrowing [Line Items]
Interest rate	5.00%
Face Value	$ 20,000
Current Coupon Rate	5.00%
LIBOR | TriCo Cap Trust I | Subordinated Debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. LIBOR +	3.05%
LIBOR | TriCo Cap Trust II | Subordinated Debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. LIBOR +	2.55%
LIBOR | North Valley Trust II | Subordinated Debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. LIBOR +	3.25%
LIBOR | North Valley Trust III | Subordinated Debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. LIBOR +	2.80%
LIBOR | North Valley Trust IV | Subordinated Debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. LIBOR +	1.33%