TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net income	$ 125,419	$ 117,655	$ 64,814
Adjustments to reconcile net income to net cash provided by operating activities:
Equity compensation vesting expense	3,869	2,638	2,036
Net cash from operating activities	162,895	132,207	114,802
Investing activities:
Sales or maturities of investments	4,234	0	0
Financing activities:
Issuance of common stock through option exercise	1,190	144	198
Repurchase of common stock	(27,148)	(4,344)	(26,720)
Cash dividends paid — common	(35,797)	(29,724)	(26,303)
Net cash from financing activities	(100,862)	850,474	1,094,575
Net change in cash and cash equivalents	(661,191)	98,870	393,044
Cash and cash equivalents at beginning of year	768,421	669,551	276,507
Cash and cash equivalents at end of year	107,230	768,421	669,551
Parent
Operating activities:
Net income	125,419	117,655	64,814
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed equity in earnings of Tri Counties Bank	(64,896)	(88,289)	(3,851)
Equity compensation vesting expense	3,869	2,638	2,036
Net change in other assets and liabilities	(3,834)	(6,427)	(1,885)
Net cash from operating activities	60,558	25,577	61,114
Financing activities:
Issuance of common stock through option exercise	1,190	144	198
Repurchase of common stock	(27,148)	(4,344)	(26,720)
Cash dividends paid — common	(35,797)	(29,724)	(26,303)
Net cash from financing activities	(61,755)	(33,924)	(52,825)
Net change in cash and cash equivalents	3,037	(8,347)	8,289
Cash and cash equivalents at beginning of year	4,950	13,297	5,008
Cash and cash equivalents at end of year	$ 7,987	$ 4,950	$ 13,297