Basis of Presentation, Benefit Plans (Details)	12 Months Ended
Dec. 31, 2021
Benefit Plans [Abstract]
Age at which company provides access to Medicare Supplemental program for retirees	65 years

The age of retirees that the company provides access to Medicare Supplemental program, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

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