TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Assets
Cash and cash equivalents	$ 107,230	$ 768,421
Other assets	257,975	109,025
Total assets	9,930,986	8,614,787
Liabilities and shareholders’ equity
Other liabilities	159,741	112,070
Junior subordinated debt	101,040	58,079
Total liabilities	8,884,570	7,614,603
Shareholders’ equity:
Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at December 31, 2020 and 2019	0	0
Common stock, no par value: 50,000,000 shares authorized; issued and outstanding: 33,331,513 and 29,730,424 at December 31, 2022 and 2021, respectively	697,448	532,244
Retained earnings	542,873	466,959
Accumulated other comprehensive income (loss), net	(193,905)	981
Total shareholders’ equity	1,046,416	1,000,184	$ 925,114	$ 893,587
Total liabilities and shareholders’ equity	9,930,986	8,614,787
Parent
Assets
Cash and cash equivalents	7,987	4,950
Investment in Tri Counties Bank	1,138,429	1,047,577
Other assets	1,818	6,073
Total assets	1,148,234	1,058,600
Liabilities and shareholders’ equity
Other liabilities	778	337
Junior subordinated debt	101,040	58,079
Total liabilities	101,818	58,416
Shareholders’ equity:
Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at December 31, 2020 and 2019	0	0
Common stock, no par value: 50,000,000 shares authorized; issued and outstanding: 33,331,513 and 29,730,424 at December 31, 2022 and 2021, respectively	697,448	532,244
Retained earnings	542,873	466,959
Accumulated other comprehensive income (loss), net	(193,905)	981
Total shareholders’ equity	1,046,416	1,000,184
Total liabilities and shareholders’ equity	$ 1,148,234	$ 1,058,600