Consolidated Statements of Cash Flows - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net loss	$ (46,948)	$ (37,652)	$ (28,358)
Adjustments to reconcile net loss to net cash and cash equivalents used in operating activities:
Depreciation	1,248	807	983
Amortization of intangible assets	2,185	503	500
Amortization of debt discount and debt issuance costs	142	83	103
Remeasurement of fair value of preferred stock warrant liability			1,800
Accretion/amortization of bond discount/premium			52
Stock-based compensation	3,311	1,840	941
Loss on disposal of property and equipment	34	86	31
Impairment loss on property and equipment			450
Deferred tax benefit	(1,024)
Change in fair value of contingent consideration	(400)
Changes in operating assets and liabilities, net of effect of acquisition:
Accounts receivable	133	55	402
Interest receivable	(5)	67	(52)
Inventories	(1,928)	701	731
Other current and long term assets	(1,974)	(170)	(328)
Restricted cash	250	125
Accounts payable	1,096	(36)	641
Accrued expenses	5,371	363	868
Net cash and cash equivalents used in operating activities	(38,509)	(33,228)	(21,236)
Investing Activities
Purchase of investments			(6,240)
Proceeds from sale and maturities of investments		6,191	904
Cash received in acquisition of a business, net of cash paid			246
Proceeds from sale of property and equipment		25
Payments for acquisition of a business	(25,000)
Purchase of property and equipment	(1,234)	(2,174)	(1,377)
Net cash and cash equivalents (used in) provided by investing activities	(26,234)	4,042	(6,467)
Financing Activities
Payment of debt		(2,877)	(1,519)
Proceeds from issuance of common stock, net of issuance costs	58,331	52,433
Proceeds from issuance of debt, net of debt discount	9,887	4,291	1,998
Proceeds from issuance of preferred stock, net of issuance costs			28,199
Taxes paid related to net share settlement of vesting of restricted stock units	(73)
Proceeds from exercise of stock options and warrants	259	91	143
Net cash and cash equivalents provided by financing activities	68,404	53,938	28,821
Effect of exchange rate changes on cash and cash equivalents	22
Net increase in cash and cash equivalents	3,683	24,752	1,118
Cash and Cash Equivalents, beginning of period	34,766	10,014	8,896
Cash and Cash Equivalents, end of period	38,449	34,766	10,014
Supplemental Disclosure for Cash Flow Information
Interest paid	$ 973	$ 904	824
Supplemental Schedule of Noncash Investing and Financing Activities
Issuance of common stock warrants	97	54
Contingent consideration related to acquisition	$ 23,900
Issuance of common stock related to acquisition	$ 43,677
Conversion of bridge notes to preferred stock			1,998
Conversion of preferred stock warrants to common stock warrants			1,909
Conversion of preferred stock to common stock			$ 30,197