Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 2,685	$ 2,852
Property and equipment, accumulated depreciation	48,797	51,099
Intangible assets, accumulated amortization	$ 24,703	$ 20,656
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	19,026,393	18,787,816
Common stock, shares outstanding	17,743,971	17,128,825
Treasury stock, shares outstanding	1,282,422	1,658,991