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TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Net income	$ 8,336us-gaap_NetIncomeLoss	$ 5,650us-gaap_NetIncomeLoss	$ 8,234us-gaap_NetIncomeLoss	$ 4,859us-gaap_NetIncomeLoss	$ 7,365us-gaap_NetIncomeLoss
Other comprehensive loss, net of tax:
Increase (decrease) in unrealized gains on available for sale securities arising during the period	9				(60)
Change in minimum pension liability	111				5
Other comprehensive loss	120				(55)
Comprehensive income	8,456us-gaap_ComprehensiveIncomeNetOfTax				7,310us-gaap_ComprehensiveIncomeNetOfTax
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	8,336				7,365
Other comprehensive loss, net of tax:
Increase (decrease) in unrealized gains on available for sale securities arising during the period	9				(60)
Change in minimum pension liability	111				5
Other comprehensive loss	120				(55)
Comprehensive income	$ 8,456				$ 7,310