Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 274,723	$ 122,420
Short-term investments	115,590	195,425
Accounts receivable	12,278	5,228
Inventory	30,445	12,813
Restricted investment		10,695
Asset held for sale	1,529
Other current assets	22,742	26,895
Total current assets	457,307	373,476
Restricted cash and investments	784	784
Property and equipment, net of accumulated depreciation of $31,488 and $30,346 as of March 31, 2017 and December 31, 2016, respectively	38,412	37,801
Intangible assets, net of accumulated amortization of $2,758 and $3,134 as of March 31, 2017 and December 31, 2016, respectively	7,684	8,076
Other non-current assets	7,346	3,967
Total assets	511,533	424,104
Current liabilities:
Accounts payable	27,446	29,690
Accrued expenses	31,157	31,016
Current portion of long-term debt	11,346	10,108
Deferred revenue	3,303	3,303
Other current liabilities	1,377	1,305
Total current liabilities	74,629	75,422
Long-term debt	2,343	6,042
Deferred rent and other	5,419	5,949
Total liabilities	82,391	87,413
Commitments and contingencies (Note 15)
Stockholders’ equity:
Preferred stock, $0.0001 par value, 3,333,333 shares authorized; none issued and outstanding
Common stock, $0.0001 par value, 99,000,000 shares authorized; 54,940,604 and 54,759,234 issued and outstanding at March 31, 2017 and December 31, 2016, respectively	5	5
Additional paid-in capital	1,511,422	1,503,126
Accumulated other comprehensive loss	(55)	(120)
Accumulated deficit	(1,082,230)	(1,166,320)
Total stockholders’ equity	429,142	336,691
Total liabilities and stockholders’ equity	$ 511,533	$ 424,104

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).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
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.