Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Stockholders equity:
Preferred stock, par value	$ 1.00	$ 1.00
Preferred stock, authorized shares	1,000,000	1,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value	$ 0.60	$ 0.60
Common stock, authorized shares	20,000,000	20,000,000
Common stock, issued shares	13,986,871	13,962,366
Common stock, outstanding shares	12,536,471	12,511,966
Treasury stock, shares	1,450,400	1,450,400