Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 22,106	$ 20,994
Accounts receivable, net	6,521	6,573
Inventories	5,897	5,621
Prepaid expenses and other current assets	2,152	1,539
Total current assets	36,676	34,727
Property and equipment, net	15,127	13,366
Intangible assets, net	817	969
Goodwill	9,056	8,342
Other assets	79	167
Total assets	61,755	57,571
Liabilities, contingently redeemable preferred stock, and stockholders’ equity
Accounts payable	4,607	3,893
Accrued expenses and other	5,739	5,271
Deferred revenue	7,444	5,624
Current portion of long-term debt	535	204
Total current liabilities	18,325	14,992
Long-term debt, net of current portion	3,369	2,203
Other noncurrent liabilities	148	56
Total liabilities	21,842	17,251
Commitments and contingencies
Contingently redeemable series C preferred stock, 0 and 0.55 shares issued and outstanding at September 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 September 30, 2017 and December 31, 2016, respectively (liquidation preference of $0 and $13 as of September 30, 2017 and December 31, 2016, respectively)
Common stock $0.01 par value; 150,000 shares authorized; 12,257 issued and 10,844 outstanding at September 30, 2017 and December 31, 2016	123	123
Additional paid-in capital	291,857	290,636
Treasury stock (at cost), 1,413 shares at September 30, 2017 and December 31, 2016	(8,601)	(8,601)
Accumulated deficit	(240,128)	(237,360)
Accumulated other comprehensive loss	(3,338)	(5,028)
Total stockholders’ equity	39,913	39,770
Total liabilities, contingently redeemable preferred stock, and stockholders’ equity	$ 61,755	$ 57,571