Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net loss	$ (16,833)	$ (15,824)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization of property and equipment	15,331	13,435
Amortization of intangible assets	2,858	3,334
Unrealized foreign exchange differences	57	1,338
Amortization of debt discount and transaction costs	5,377	5,044
Asset Impairment Charges	0	224
Stock-based compensation expense	18,839	15,799
Excess tax benefits from stock-based compensation expense	0	(53)
Other non-cash items	547	28
Changes in operating assets and liabilities:
Accounts receivable	3,722	(8,949)
Inventory, net	(8,058)	(9,267)
Prepaid expenses and other current assets	(4,252)	(5,151)
Other non-current assets	(91)	(207)
Accounts payable and other current and non-current liabilities	6,024	9,695
Accrued compensation	(3,071)	(2,514)
Deferred revenue	4,288	991
Net cash provided by operating activities	24,738	7,923
Cash flows from investing activities:
Capital expenditures	(34,167)	(19,308)
Cost of acquisitions, net	0	(3,000)
Proceeds from sale of equipment and an intangible asset	44	834
Proceeds from sales of marketable securities and investments	40,730	44,873
Proceeds from maturities of marketable securities and investments	112,313	118,497
Purchases of marketable securities and investments	(158,527)	(156,401)
Transfer from (to) restricted cash	(2,049)	1,328
Net cash used in investing activities	(41,656)	(13,177)
Cash flows from financing activities:
Net proceeds from the issuance of common shares and exercise of stock options	4,836	20,592
Excess tax benefits from stock-based compensation expense	0	53
Principal payment of notes payable	(85)	(80)
Net cash provided by financing activities	4,751	20,565
Effect of foreign exchange rate change on cash and cash equivalents	(70)	(1,405)
Net increase (decrease) in cash and cash equivalents	(12,237)	13,906
Cash and cash equivalents at beginning of period	112,568	96,663
Cash and cash equivalents at end of period	$ 100,331	$ 110,569