Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Allowance for doubtful accounts	$ 585	$ 24,629
Common stock, par value		$ 0.001
Common stock, shares authorized		25,000,000
Common stock, shares issued		15,799,318
Common stock, shares outstanding		14,826,906
Treasury Stock, Shares		972,412
Common Class A [Member]
Common stock, par value	$ 0.01
Common stock, shares authorized	50,000,000
Common stock, shares issued	19,998,695
Common stock, shares outstanding	19,998,695
Common Class B [Member]
Common stock, par value	$ 0.01
Common stock, shares authorized	2,000,000
Common stock, shares issued	113,840
Common stock, shares outstanding	76,269