Basis of Presentation, Allowance for Loan Losses (Details)	12 Months Ended
Dec. 31, 2021 Payment
Allowance for Loan Losses [Abstract]
Number of past due payments on loans classified as nonperforming	3
Loan-to-value ratio applicable to additional allowance	90.00%

The loan-to-value ratio that the company's allowance methodology also includes additional allocation percentage for during the period.

No definition available.

Name:	trst_LoanToValueRatioApplicableToAdditionalAllowance
Namespace Prefix:	trst_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration