Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Consolidated Balance Sheets [Abstract]
Allowance for doubtful accounts	$ 24,629	$ 12,156
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	25,000,000	25,000,000
Common stock, shares issued	15,799,318	15,689,463
Common stock, shares outstanding	14,826,906	14,717,051
Treasury stock at cost, shares	972,412	972,412