CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows From Operating Activities:
Net loss	$ (30,781)	$ (20,849)	$ (19,037)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization of property and equipment	1,724	1,645	1,330
Amortization of intangible assets	1,495	1,037	842
Changes in fair value of warrant and earnout liabilities	1,313	249
Amortization of patents	23	31
Amortization and write-off of senior debt fees	576	627	141
Gain on sale of equipment	(831)	(824)	(601)
Provision for bad debts		(264)	227
Loss on impairment of intangible assets			544
Share-based compensation expense	1,181	210	101
Interest accrued on note payable	548	511	592
Change in deferred rent	(23)	41	385
Changes in operating assets and liabilities:
Accounts receivable	(3,536)	417	971
Inventories	(489)	(1,612)	637
Other current assets	(794)	(167)	(97)
Other assets	(266)	(231)	(343)
Accounts payable	3,567	284	(349)
Accrued expenses	426	1,505	(298)
Net cash used in operating activities	(25,867)	(17,390)	(14,955)
Cash Flows From Investing Activities:
Net proceeds from sale of short-term investments	3,000	4,497	(7,498)
Capital expenditures	(1,023)	(339)	(2,019)
Intangible asset acquisition		(6,283)
Net cash provided by (used in) investing activities	1,977	(2,125)	(9,517)
Cash Flows from Financing Activities:
Proceeds from senior debt note	10,000	15,000
Proceeds from sale of equipment		795	5,500
Net proceeds from issuance of stock	18,122	17,350	8,523
Net proceeds from initial public offering, net of underwriting discounts, commissions and offering costs	75,013
Payments made on borrowings	(1,654)	(11,671)	(890)
Payments made to purchase treasury stock	(171)
Deferred financing costs		(563)
Net cash provided by financing activities	101,310	20,911	13,133
Increase (decrease) in cash and cash equivalents	77,420	1,396	(11,339)
Cash and Cash Equivalents:
Beginning	13,343	11,947	23,286
Ending	90,763	13,343	11,947
Noncash Investing and Financing Activities:
Earout liability incurred in connection with intangible assets acquisition		589
Issuance of stock warrants	2,131	1,707
Exercise of Series c warrants for Series C Preferred Stock	2,322
Cashless exercise of Series C warrants from Series C financing in IPO closing	2,842
Conversion of Redeemable Preferred Stocks into Common Stock	110,776
Reclassification of Series C warrants issued with senior debt upon IPO closing	611
Preferred Stock Accretion	1,169	1,118	1,227
Preferred Stock Dividend	1,221	2,185	2,185
Supplemental Cash Flow Information:
Interest paid	$ 2,524	$ 1,793	$ 1,324