Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investment securities:
Held-to-maturity, at fair value	$ 67,631	$ 68,457
Stockholders Equity
Common stock, par value (in dollars per share)	$ 4	$ 4
Common stock, authorized (in shares)	18,000,000	18,000,000
Common stock, issued (in shares)	13,248,323	13,231,225
Treasury stock (in shares)	570,477	570,477