Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 21,464	$ 20,994
Accounts receivable, net	6,900	6,573
Inventories	5,212	5,621
Prepaid expenses and other current assets	1,812	1,539
Total current assets	35,388	34,727
Property and equipment, net	14,811	13,366
Intangible assets, net	869	969
Goodwill	8,793	8,342
Other assets	167	167
Total assets	60,028	57,571
Liabilities, contingently redeemable preferred stock, and stockholders’ equity
Accounts payable	3,461	3,893
Accrued expenses and other	5,134	5,271
Deferred revenue	7,191	5,624
Current portion of long-term debt	516	204
Total current liabilities	16,302	14,992
Long-term debt, net of current portion	3,398	2,203
Other noncurrent liabilities	32	56
Total liabilities	19,732	17,251
Commitments and contingencies
Contingently redeemable series C preferred stock, 0 and 0.55 shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively (liquidation preference of $550)		550
Stockholders’ equity:
Preferred stock, $0.01 par value; 1,000 shares authorized Series B convertible preferred stock, 0 and 0.13 shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively (liquidation preference of $13)
Common stock $0.01 par value; 150,000 shares authorized; 12,257 issued and 10,844 outstanding at June 30, 2017 and December 31, 2016	123	123
Additional paid-in capital	291,469	290,636
Treasury stock (at cost), 1,413 shares at June 30, 2017 and December 31, 2016	(8,601)	(8,601)
Accumulated deficit	(238,718)	(237,360)
Accumulated other comprehensive loss	(3,977)	(5,028)
Total stockholders’ equity	40,296	39,770
Total liabilities, contingently redeemable preferred stock, and stockholders’ equity	$ 60,028	$ 57,571