Consolidated Balance Sheets (unaudited) (Parenthetical) - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Stockholders' equity:
Common stock, par value (in dollars per share)	$ 5	$ 5
Common stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, shares outstanding (in shares)	5,181,106	5,019,703
Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested restricted stock (in shares)	12,083	2,245

Face amount or stated value per share of common stock.

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