Building Held for Sale (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Building Held for Sale [Abstract]
Agreement to sell operations center		$ 5.0
Carrying value of building to be used as operations center		$ 3.2
Recognized gain from the sale of the building	$ 1.6

Refers to the estimated purchase price to be received from a third party for a building the Company had planned to utilize as a regional operations center in Florida.

No definition available.

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