TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended							9 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Financial Statements, Captions [Line Items]
Net income	$ 8,234	$ 4,859	$ 7,365	$ 5,236	$ 7,361	$ 6,325	$ 8,477	$ 20,458	$ 22,163
Other comprehensive income (loss), net of tax:
Unrealized holding gains (losses) on available for sale securities arising during the period	(398)				83			(77)	(2,027)
Change in minimum pension liability	6							16
Other comprehensive income (loss)	(392)				83			(61)	(2,027)
Comprehensive income	7,842				7,444			20,397	20,136
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	8,234				7,361			20,458	22,163
Other comprehensive income (loss), net of tax:
Unrealized holding gains (losses) on available for sale securities arising during the period	(398)				83			(77)	(2,027)
Change in minimum pension liability	6							16
Other comprehensive income (loss)	(392)				83			(61)	(2,027)
Comprehensive income	$ 7,842				$ 7,444			$ 20,397	$ 20,136