Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Allowance for doubtful accounts	$ 680	$ 654
LIABILITIES AND STOCKHOLDERS’ EQUITY
Preferred stock, par value (in USD per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	500,000	500,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	35,000,000	35,000,000
Common stock, shares issued (in shares)	9,304,366	9,287,625
Common stock, shares outstanding (in shares)	9,077,512	9,061,039
Treasury stock (in shares)	226,854	226,586