Foreclosed Assets - Summary of Activity in Balance of Foreclosed Assets (Detail) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) Assets	Sep. 30, 2017 USD ($) Assets
Goodwill and Intangible Assets Disclosure [Abstract]
Beginning balance, net			$ 3,226	$ 3,986
Additions/transfers from loans			536	726
Dispositions/sales			(1,841)	(1,479)
Valuation adjustments			(89)	(162)
Ending balance, net	$ 1,832	$ 3,071	1,832	3,071
Ending valuation allowance			$ (143)	$ (248)
Ending number of foreclosed assets \| Assets			11	11
Proceeds from sale of foreclosed assets			$ 2,206	$ 1,787
Gain on sale of foreclosed assets	$ 2	$ 37	$ 390	$ 308

Additions (Reductions) transfers from loans related to foreclosed assets.

No definition available.

Name:	tcbk_AdditionsReductionsTransfersFromLoansRelatedToForeclosedAssets
Namespace Prefix:	tcbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Ending number of foreclosed assets.

+ References

No definition available.

+ Details

Name:	tcbk_EndingNumberOfForeclosedAssets
Namespace Prefix:	tcbk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Ending valuation allowance.

+ References

No definition available.

+ Details

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

- Definition

Loss (gain) on sale of foreclosed assets.

+ References

No definition available.

+ Details

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

- Definition

Carrying amount as of the balance sheet date of all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings or defeasance; includes real and personal property; equity interests in corporations, partnerships, and joint ventures; and beneficial interests in trusts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5162-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4437-111522

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Disposals of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This excludes real estate assets taken in settlement of troubled loans through surrender or foreclosure.

+ References

No definition available.

+ Details

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

- Definition

Valuation adjustments made to other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This excludes real estate assets taken in settlement of troubled loans through surrender or foreclosure.

+ References

No definition available.

+ Details

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

- Definition

The cash inflow from the sale assets received in full or partial satisfaction of a receivable including real and personal property; equity interests in corporations, partnerships, and joint ventures; and beneficial interests in trusts. Foreclosed assets also include loans that are treated as if the underlying collateral had been foreclosed because the institution has taken possession of the collateral, even though legal foreclosure or repossession proceedings have not taken place.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromSaleOfForeclosedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration