CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable, allowance (in dollars)	$ 1,191	$ 675
Accumulated depreciation of property and equipment	$ 12,689	$ 13,043
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized shares	5,000,000	5,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	50,000,000	50,000,000
Common stock, issued shares	15,138,620	14,218,572
Common stock, outstanding shares	12,742,751	11,979,434
Treasury stock, shares	2,395,869	2,239,138