Parent Company (Franklin Financial Services Corporation) Financial Information (Schedule Of Condensed Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Other									$ 390	$ 109	$ 240
OTTI loss on equity securities											(50)
Securities gains, net			$ 8	$ 718	$ 59	$ (20)	$ 221		8	280	33
Income before federal income tax expense	$ 2,760	$ 2,885	3,106	3,723	2,194	3,051	2,925	$ 2,238	12,475	10,408	7,527
Federal income tax expense	493	306	632	839	347	641	606	412	2,271	2,006	1,295
Net income	$ 2,267	$ 2,579	$ 2,474	$ 2,884	$ 1,847	$ 2,410	$ 2,319	$ 1,826	10,204	8,402	6,232
Franklin Financial Service Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Dividends from Bank subsidiary									300	1,151	2,529
Interest and dividend income										15	31
Other									171
OTTI loss on equity securities											(50)
Securities gains, net										82	30
Income									471	1,248	2,540
Operating Expenses									986	795	752
Income before federal income tax expense									(515)	453	1,788
Federal income tax expense									(328)	(241)	(259)
Equity in undistributed income of subsidiary									10,391	7,708	4,185
Net income									$ 10,204	$ 8,402	$ 6,232