Name:	trst_ProceedsFromPrepaymentsAndCallsOfAvailableForSaleSecurities
Namespace Prefix:	trst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

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

The sale of available for sale securities during the period.

No definition available.

Name:	trst_SalesOfAvailableForSaleSecurities
Namespace Prefix:	trst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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

Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e640-108580

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

The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26853-111562

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a),(b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585