Junior Subordinated Debt - Summary of Terms and Recorded Balance of Subordinated Debenture (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 101,120	$ 101,099
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	8.63%
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	8.13%
North Valley Trust II
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 5,629	5,602
North Valley Trust II | Subordinated debt
Subordinated Borrowing [Line Items]
Face Value	$ 6,186
Current Coupon Rate	8.82%
North Valley Trust III
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 4,495	4,472
North Valley Trust III | Subordinated debt
Subordinated Borrowing [Line Items]
Face Value	$ 5,155
Current Coupon Rate	8.38%
North Valley Trust IV
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 7,673	7,615
North Valley Trust IV | Subordinated debt
Subordinated Borrowing [Line Items]
Face Value	$ 10,310
Current Coupon Rate	6.92%
VRB Subordinated
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 16,953	17,000
VRB Subordinated | Subordinated debt
Subordinated Borrowing [Line Items]
Face Value	$ 16,000
Current Coupon Rate	9.08%
VRB Subordinated - 5%
Subordinated Borrowing [Line Items]
Recorded Book Value	$ 25,132	$ 25,172
VRB Subordinated - 5% | Subordinated debt
Subordinated Borrowing [Line Items]
Interest rate	5.00%
Face Value	$ 20,000
Current Coupon Rate	5.00%
SOFR PLUS | TriCo Cap Trust I | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. SOFR +	3.05%
SOFR PLUS | TriCo Cap Trust II | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. SOFR +	2.55%
SOFR PLUS | North Valley Trust II | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. SOFR +	3.25%
SOFR PLUS | North Valley Trust III | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. SOFR +	2.80%
SOFR PLUS | North Valley Trust IV | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. SOFR +	1.33%
SOFR PLUS | VRB Subordinated | Subordinated debt
Subordinated Borrowing [Line Items]
Coupon Rate (Variable) 3 mo. SOFR +	3.52%