Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	10,000,000	10,000,000
Common stock, issued (in shares)	7,555,167	7,290,167
Common stock, outstanding (in shares)	7,156,281	6,918,579
Treasury stock, shares (in shares)	398,886	371,588
Series A Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.50	$ 0.50
Preferred stock, outstanding (in shares)	0	0
Preferred stock, authorized (in shares)	700,000	700,000