TriCo Bancshare Condensed Financial Statements (Parent Only) - Condensed Statements of Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Jun. 30, 2015
Condensed Financial Statements, Captions [Line Items]
Net income	$ 9,405	$ 10,674	$ 11,422	$ 12,694	$ 11,366	$ 8,336	$ 20,079	$ 19,702
Other comprehensive income (loss), net of tax:
Unrealized holding gains (losses) on available for sale securities arising during the period	4,157				(2,754)		7,707	(2,745)
Change in minimum pension liability	(148)				(111)		(148)	(222)
Change in joint beneficiary agreement liability	(4)						(4)
Other comprehensive income (loss)	4,301				(2,643)		7,851	(2,523)
Comprehensive income	13,706				8,723		27,930	17,179
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	9,405				11,366		20,079	19,702
Other comprehensive income (loss), net of tax:
Unrealized holding gains (losses) on available for sale securities arising during the period	4,157				(2,754)		7,707	(2,745)
Change in minimum pension liability	148				111		148	222
Change in joint beneficiary agreement liability	(4)						(4)
Other comprehensive income (loss)	4,301				(2,643)		7,851	(2,523)
Comprehensive income	$ 13,706				$ 8,723		$ 27,930	$ 17,179