Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 60,981	$ 78,889
Accounts receivable, net	63,482	36,868
Inventories, net	110,582	109,408
Prepaid expenses and other current assets	7,658	4,792
Total current assets	242,703	229,957
Property, plant and equipment, net	31,057	30,031
Long-term restricted cash	6,862	6,936
Other assets	18,666	14,860
Total assets	299,288	281,784
Current liabilities
Accounts payable	26,836	19,849
Accrued compensation	5,935	9,059
Warranty	2,958	3,363
Income taxes	196	143
Deferred revenue	13,781	7,863
Other current liabilities	4,584	4,091
Total current liabilities	54,290	44,368
Sale leaseback obligation	47,586	47,586
Long-term deferred revenue	650	679
Other long-term liabilities	4,950	5,387
Total liabilities	107,476	98,020
Commitments and contingencies (Note 14)
Stockholders' equity
Common stock, $0.001 par value, 75,000 shares authorized; 29,134 shares issued and outstanding at June 30, 2016; 29,025 shares issued and 28,995 shares outstanding at December 31, 2015	29	29
Additional paid-in capital	530,389	529,089
Treasury stock, at cost, no shares at June 30, 2016 and 30 at December 31, 2015		(1,218)
Accumulated deficit	(337,820)	(342,705)
Accumulated other comprehensive loss	(786)	(1,431)
Total stockholders' equity	191,812	183,764
Total liabilities and stockholders' equity	$ 299,288	$ 281,784