Subordinated Debentures - Summary of Terms and Recorded Balance of Subordinated Debenture (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 100,984	$ 58,079
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	3.29%
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	2.67%
North Valley Trust II
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 5,428	5,403
North Valley Trust II | Subordinated debt
Subordinated Borrowing [Line Items]
Face Value	$ 6,186
Current Coupon Rate	3.38%
North Valley Trust III
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 4,315	4,291
North Valley Trust III | Subordinated debt
Subordinated Borrowing [Line Items]
Face Value	$ 5,155
Current Coupon Rate	2.92%
North Valley Trust IV
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 7,211	7,147
North Valley Trust IV | Subordinated debt
Subordinated Borrowing [Line Items]
Face Value	$ 10,310
Current Coupon Rate	1.53%
VRB Subordinated - 6%
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 17,774	0
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	$ 25,018	$ 0
VRB Subordinated - 5% | Subordinated debt
Subordinated Borrowing [Line Items]
Interest rate	5.00%
Face Value	$ 20,000
Current Coupon Rate	5.00%
LIBOR PLUS | TriCo Cap Trust I | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. LIBOR +	3.05%
LIBOR PLUS | TriCo Cap Trust II | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. LIBOR +	2.55%
LIBOR PLUS | North Valley Trust II | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. LIBOR +	3.25%
LIBOR PLUS | North Valley Trust III | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. LIBOR +	2.80%
LIBOR PLUS | North Valley Trust IV | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. LIBOR +	1.33%