Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Consolidated Balance Sheets [Abstract]
Allowance for doubtful accounts	$ 12,156	$ 12,080
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	15,689,463	15,488,542
Common stock, shares outstanding	14,717,051	15,488,542
Treasury stock at cost, shares	972,412	0