Deposits (Maturity Of Time Deposits Of $250,000 Or More) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deposits [Abstract]
Within three months	$ 9,964
Over three through six months	628
Over six through twelve months	755
Over twelve months	672
Total	$ 12,019	$ 6,200

Contractual Maturities Time Deposits 250000 Or More Three Months Through Six Months

No definition available.

Name:	fraf_ContractualMaturitiesTimeDeposits250000OrMoreThreeMonthsThroughSixMonths
Namespace Prefix:	fraf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant