Allowance for Loan Losses - Additional Information (Detail) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Interest income on non accrual loans	$ 1,584,000	$ 1,067,000	$ 783,000
Interest income on non accrual loans ,recognized	486,000	530,000	377,000
Impaired TDR Loans	10,253,000	12,517,000	12,371,000
Obligations to lend additional funds on TDR	0	0	0
PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Interest income on non accrual loans	1,122,000	73,000	178,000
Interest income on non accrual loans ,recognized	989,000	18,000	11,000
Impaired TDR Loans	615,000	1,352,000	1,324,000
Obligations to lend additional funds on TDR	$ 0	$ 0	$ 0

Interest income recognized on nonaccrual loans.

No definition available.

Name:	tcbk_InterestIncomeRecognizedOnNonaccrualLoans
Namespace Prefix:	tcbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Obligation related to troubled debt restructuring.

+ References

No definition available.

+ Details

Name:	tcbk_ObligationRelatedToTroubledDebtRestructuring
Namespace Prefix:	tcbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

+ Details

Name:	us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_LoansAndLeasesReceivableDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18794-111554

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_CreditLossStatusAxis=us-gaap_FinancialAssetOriginatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: