CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 53,814	$ 35,944
Short-term investments	328,628	136,653
Accounts receivable, net	27,467	29,937
Inventories, net	33,602	31,278
Prepaid expenses and other current assets	7,480	9,277
Total current assets	450,991	243,089
Fixed assets, net	103,239	101,016
Goodwill	50,943	46,737
Other assets	572	624
Total assets	605,745	391,466
Current liabilities:
Accounts payable	10,392	7,511
Accrued expenses	46,755	37,261
Convertible senior notes	319	0
Income taxes payable	44	66
Total current liabilities	57,510	44,838
Convertible senior notes	269,328	108,738
Other liabilities	17,859	18,914
Total liabilities	344,697	172,490
Commitments and contingencies (Note 12)
Stockholders’ equity:
Preferred stock, par value $0.001; 5,000,000 shares authorized; none issued and outstanding at June 30, 2017 and December 31, 2016	0	0
Common stock, par value $0.001, 250,000,000 shares authorized; 40,318,129 shares issued and outstanding at June 30, 2017; 37,480,952 shares issued and outstanding at December 31, 2016	40	37
Additional paid-in capital	647,206	565,207
Accumulated deficit	(386,134)	(346,238)
Accumulated other comprehensive loss	(64)	(30)
Total stockholders’ equity	261,048	218,976
Total liabilities and stockholders’ equity	$ 605,745	$ 391,466

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.