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	$ (114,507)	$ (24,215)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,229	2,933
Stock-based compensation	6,768	4,619
Change in fair value of derivative liabilities	43,831	0
Change in fair value of contingent consideration related to acquisition	100	200
Accretion of interest & amortization of deferred financing costs on convertible notes	4,603	1,981
Non-cash foreign exchange loss (gain)	810	(655)
Changes in operating assets and liabilities:
Accounts receivable and other receivables	(2,445)	(3,195)
Inventories	3,557	739
Prepaid expenses and other current assets	1,100	413
Accounts payable	(5,812)	2,692
Accrued payroll	6,922	(1,689)
Accrued expenses and other liabilities	1,889	(207)
Net cash used in operating activities	(48,955)	(16,384)
Cash flows from investing activities:
Purchases of marketable securities	(5,017)	(37,122)
Maturities of marketable securities	19,350	62,690
Purchases of property and equipment	(1,304)	(3,146)
Acquisition of business, net of cash acquired of $24,012	(60,622)	0
Net cash (used in) provided by investing activities	(47,593)	22,422
Cash flows from financing activities:
Proceeds from sale of common stock under employee stock purchase plan	1,826	1,631
Proceeds from exercise of stock options	1,777	2,628
Minimum tax withholding paid on behalf of employees for restricted stock units	(134)	(291)
Net cash provided by financing activities	3,469	3,968
Effect of exchange rate changes on cash and cash equivalents	(26)	(535)
Net (decrease) increase in cash and cash equivalents	(93,105)	9,471
Cash and cash equivalents, beginning of period	124,553	26,798
Cash and cash equivalents, end of period	31,448	36,269
Supplemental disclosure of cash flow information:
Cash paid for interest	2,994	973
Cash paid for income taxes	167	140
Non-cash investing and financing activities:
Landlord funded leasehold improvements	0	46
Acquisition of property and equipment included in accounts payable	36	71
Fair value of common stock issued for business acquisition	100,812	0
Fair value of warrants issued for business acquisition	$ 44	$ 0