Name:	trst_CollateralDependentImpairedFinancingReceivableRecordedInvestment
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Data Type:	xbrli:monetaryItemType
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- References

No definition available.

Name:	trst_FairValueAssetsAndLiabilitiesMeasuredOnNonrecurringBasisAbstract
Namespace Prefix:	trst_
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Reflects the amount of loans and leases that have been removed, or charged off, from both loan receivables and the reserve for credit losses, typically because they are considered to be not salvageable or have been purchased by unconsolidated collection entities.

No definition available.

Name:	trst_GrossChargeOffsResidentialImpairedLoans
Namespace Prefix:	trst_
Data Type:	xbrli:monetaryItemType
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Period Type:	duration

The fair value disclosure of commercial real estate included in other real estate owned.

No definition available.

Name:	trst_OtherRealEstateOwnedCommercialRealEstateFairValueDisclosure
Namespace Prefix:	trst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents other real estate owned and held at period end.

No definition available.

Name:	trst_OtherRealEstateOwnedFairValueDisclosure
Namespace Prefix:	trst_
Data Type:	xbrli:monetaryItemType
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The fair value disclosure of residential real estate properties included in other real estate owned.

No definition available.

Name:	trst_OtherRealEstateOwnedResidentialRealEstatePropertiesFairValueDisclosure
Namespace Prefix:	trst_
Data Type:	xbrli:monetaryItemType
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No definition available.

Name:	trst_RealEstateMortgagesOneToFourFamilyClassifiedAsImpairedFairValueDisclosure
Namespace Prefix:	trst_
Data Type:	xbrli:monetaryItemType
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Percentage of adjustment to the observed price for a similar asset or liability when an identical transaction does not exist, used as an input to measure fair value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Description of the inputs and valuation technique(s) used to measure fair value.

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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

Name:	us-gaap_ImpairedFinancingReceivableRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- References

No definition available.

Name:	us-gaap_LoanAndLeaseReceivablesImpairedAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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Amount of the valuation allowance for real estate owned that was applied in the period against the carrying amount of real estate owned that was sold, written down or written off.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(4))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

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Name:	us-gaap_FairValueByAssetClassAxis=trst_ImpairedLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialMortgageMember
Namespace Prefix:
Data Type:	na
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