Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Consolidated Balance Sheets [Abstract]
Securities available for sale, amortized cost	$ 472,903	$ 458,370
Capital stock, par value	$ 2	$ 2
Capital stock, shares authorized	20,000,000	10,000,000
Capital stock, shares issued	6,788,407	6,788,407
Prior service cost and unamortized net actuarial losses on employee benefit plans, tax	$ 256	$ 251
Net unrealized appreciation on securities available for sale, tax	2,267	3,997
Portion of OTTI attributable to non-credit losses, tax	265	257
Net unrealized appreciation on derivative instruments, tax	$ 476	$ 389
Treasury stock, shares	803,451	842,082