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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. This item represents the aggregate of all interest bearing deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits among others.

No definition available.

Name:	trst_InterestBearingDepositFairValueDisclosure
Namespace Prefix:	trst_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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 amount as of the balance sheet date of [accrued] interest payable on all forms of debt, including deposits and borrowings, that has been incurred and is unpaid.

No definition available.

Name:	trst_InterestPayableFairValueDisclosure
Namespace Prefix:	trst_
Data Type:	xbrli:monetaryItemType
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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 amount as of the balance sheet date of [accrued] interest receivable on loans, investment securities and federal funds sold and other short-term investments that has been earned and is unpaid.

No definition available.

Name:	trst_InterestReceivableFairValueDisclosure
Namespace Prefix:	trst_
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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 the amount shown on an entity's books for investments in Federal Reserve Bank and Federal Home Loan Bank stock.

No definition available.

Name:	trst_InvestmentInFederalReserveBankAndFederalHomeLoanBankStockFairValueDisclosure
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Data Type:	xbrli:monetaryItemType
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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References

No definition available.

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No definition available.

Name:	us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract
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Period Type:	duration

Fair value of investments in debt securities classified as held-to-maturity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Name:	us-gaap_HeldToMaturitySecuritiesFairValue
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Name:	us-gaap_LoansReceivableFairValueDisclosure
Namespace Prefix:	us-gaap_
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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 the amount of short-term debt existing as of the balance sheet date.

No definition available.

Name:	us-gaap_ShorttermDebtFairValue
Namespace Prefix:	us-gaap_
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