Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Preferred stock, par value (in USD per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	2,500,000	2,500,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, shares issued (in shares)	6,852,338	6,897,890
Common stock, shares outstanding (in shares)	6,852,338	6,897,890