Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Receivables allowance for doubtful accounts	$ 24	$ 24
Preferred stock, percentage non-cumulative	5.00%	5.00%
Preferred stock, par value (in dollars per share)	$ 10	$ 10
Preferred stock, shares authorized (shares)	1,000	1,000
Preferred stock, shares issued (shares)	437	437
Preferred stock, shares outstanding (shares)	437	437
Common stock, shares authorized (shares)	40,000,000	40,000,000
Common stock, shares issued (shares)	18,115,965	18,115,965
Common stock, shares outstanding (shares)	16,913,313	17,028,125
Treasury stock (shares)	1,202,652	1,087,840

Amount of allowance for credit loss on accounts receivable, classified as current.

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