Building Held for Sale (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Dec. 31, 2013	Sep. 30, 2013
Building Held for Sale [Abstract]
Agreement to sell operations center		$ 5.0
Carrying value of building to be used as a branch location		3.2
Recognize gain from the sale of the building	$ 1.8

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