CONSOLIDATED BALANCE SHEETS [Parenthetical] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Redeemable Convertible Preferred Stock, shares outstanding	22,000
Redeemable Convertible Preferred Stock, liquidation preference	$ 22,000
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	18,596,774	18,079,522
Common Stock, shares issued	16,726,610	16,253,426
Common Stock, shares outstanding	16,726,610	16,253,426
Treasury Stock, shares at cost	1,870,164	1,826,096
Redeemable Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Redeemable Convertible Preferred Stock, shares authorized	100,000,000	100,000,000
Redeemable Convertible Preferred Stock, shares outstanding	10,552,941	8,200,000
Redeemable Convertible Preferred Stock, liquidation preference	$ 51,170	$ 39,570