Name:	trst_FinancingReceivableModificationsSubsequentDefaultAbstract
Namespace Prefix:	trst_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Number of days past due when loan is considered to be in payment default under the modified terms.

No definition available.

Name:	trst_NumberOfDaysPastDueLoanConsideredInPaymentDefault
Namespace Prefix:	trst_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Number of days past due when loan is considered to be in payment default under the modified terms.

No definition available.

Name:	trst_NumberOfDaysPastDueWhenLoansConsideredInPaymentDefaultUnderModifiedTerms
Namespace Prefix:	trst_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Name:	dei_EntityByLocationAxis=trst_NewYorkAndOtherStatesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_FirstMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: