Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 48,237	$ 185,606
Marketable securities	84,153
Restricted cash	101	101
Accounts receivable, net	15,637	6,483
Inventory	8,083	3,717
Prepaid expenses and other current assets	4,470	5,487
Total current assets	160,681	201,394
Restricted cash	584	584
Property and equipment, net	20,824	21,915
Other assets	27	27
Intangible assets, net	7,211	7,355
Goodwill	3,605	3,605
Total assets	192,932	234,880
Current liabilities:
Accounts payable, accrued expenses and other	50,449	52,082
Deferred revenues	45,097	50,137
Deferred rent	1,817	1,527
Total current liabilities	97,363	103,746
Deferred revenues, net of current portion	47,103	51,197
Deferred rent, net of current portion	4,832	4,926
Deferred tax incentives, net of current portion	934	1,045
Long-term debt	259,843	257,655
Total liabilities	$ 410,075	$ 418,569
Commitments and contingencies
Non-controlling interest	$ 54	$ 239
Stockholders' deficit:
Preferred stock, $0.01 par value: 10,000 shares authorized at March 31, 2016 and December 31, 2015; no shares issued or outstanding at March 31, 2016 or December 31, 2015
Common stock, $0.01 par value: 200,000 shares authorized at March 31, 2016 and December 31, 2015, 116,411 and 115,871 shares issued and outstanding at March 31, 2016 and December 31, 2015, respectively	$ 1,164	$ 1,159
Additional paid-in capital	622,358	617,145
Accumulated other comprehensive loss	(14)
Accumulated deficit	(840,705)	(802,232)
Total stockholders' deficit	(217,197)	(183,928)
Total liabilities, non-controlling interest and stockholders' deficit	$ 192,932	$ 234,880