CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 25,309	$ 56,984
Short-term investments	137,358	101,981
Accounts receivable, net	28,651	25,855
Inventories, net	60,916	61,645
Prepaid expenses and other current assets	5,755	6,117
Total current assets	257,989	252,582
Long-term investments	0	13,462
Fixed assets, net	99,282	90,324
Goodwill	42,751	30,880
Intangible assets, net	0	81
Other assets	677	406
Total assets	400,699	387,735
Current liabilities:
Accounts payable	4,614	8,739
Accrued expenses	38,330	35,375
Convertible senior notes	106,388	104,040
Current portion of deferred revenue	1,048	1,426
Income taxes payable	58	208
Total current liabilities	150,438	149,788
Deferred revenue	7,747	8,082
Other liabilities	14,163	11,473
Total liabilities	172,348	169,343
Commitments and contingencies
Stockholders’ equity:
Preferred stock, par value $0.001; 5,000,000 shares authorized; none issued and outstanding at June 30, 2016 and December 31, 2015	0	0
Common stock, par value $0.001, 250,000,000 shares authorized; 37,273,407 shares issued and outstanding at June 30, 2016; 36,848,319 shares issued and outstanding at December 31, 2015	37	37
Additional paid-in capital	548,277	526,696
Accumulated deficit	(320,101)	(308,289)
Accumulated other comprehensive income (loss)	138	(52)
Total stockholders’ equity	228,351	218,392
Total liabilities and stockholders’ equity	$ 400,699	$ 387,735