Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 886	$ 1,822
Preferred stock par value	$ 1	$ 1
Preferred stock shares authorized	10,000,000	10,000,000
Preferred stock shares issued	0	0
Common stock par value	$ 0.01	$ 0.01
Common stock shares authorized	100,000,000	100,000,000
Common stock shares issued	31,493,328	31,048,842
Common stock shares outstanding	26,135,945	25,870,876
Treasury stock shares	5,357,383	5,177,966