TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net income	$ 117,655	$ 64,814	$ 92,072
Adjustments to reconcile net income to net cash provided by operating activities:
Equity compensation vesting expense	2,638	2,036	1,654
Net cash from operating activities	132,207	114,802	102,806
Financing activities:
Issuance of common stock through option exercise	144	198	9
Repurchase of common stock, net	(4,344)	(26,720)	(2,196)
Cash dividends paid — common	(29,724)	(26,303)	(24,999)
Net cash from financing activities	850,474	1,094,575	(24,043)
Net change in cash and cash equivalents	98,870	393,044	48,974
Cash and cash equivalents at beginning of year	669,551	276,507	227,533
Cash and cash equivalents at end of year	768,421	669,551	276,507
Parent
Operating activities:
Net income	117,655	64,814	92,072
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed equity in earnings of Tri Counties Bank	(88,289)	(3,851)	(62,326)
Equity compensation vesting expense	2,638	2,036	1,654
Net change in other assets and liabilities	(6,427)	(1,885)	(1,580)
Net cash from operating activities	25,577	61,114	29,820
Financing activities:
Issuance of common stock through option exercise	144	198	9
Repurchase of common stock, net	(4,344)	(26,720)	(2,196)
Cash dividends paid — common	(29,724)	(26,303)	(24,999)
Net cash from financing activities	(33,924)	(52,825)	(27,186)
Net change in cash and cash equivalents	(8,347)	8,289	2,634
Cash and cash equivalents at beginning of year	13,297	5,008	2,374
Cash and cash equivalents at end of year	$ 4,950	$ 13,297	$ 5,008