Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Allowances for receivables	$ 311	$ 24
Accumulated depreciation and amortization of equipment and leasehold improvements	19,748	14,805
Amortization of intangibles	3,820	$ 3,351
Restricted cash	$ 4,210
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	35,000,000	35,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	27,511,361	27,636,853
Common stock, shares outstanding	26,622,706	25,849,876
Treasury stock, shares	888,655	1,786,977
Series B Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	1,637,948	1,644,768
Preferred stock, shares outstanding	1,637,948	1,644,768
Liquidation preference	$ 10,985	$ 10,443