CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows From Operating Activities:
Net loss	$ (83,333,000)	$ (30,781,000)	$ (20,849,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	3,460,000	1,181,000	210,000
Depreciation and amortization of property and equipment	1,598,000	1,724,000	1,645,000
Amortization of intangible assets	1,593,000	1,495,000	1,037,000
Changes in fair value of warrant and earnout liabilities	18,000	1,313,000	249,000
Amortization of patents	69,000	23,000	31,000
Amortization of senior debt fees	406,000	576,000	182,000
Amortization of short-term investment purchase discounts	(156,000)
Deferred interest on debt	4,738,000	548,000	511,000
Loss on debt extinguishment	942,000		445,000
Gain on sale of equipment	(922,000)	(831,000)	(824,000)
Change in deferred rent	8,000	(23,000)	41,000
Realized gain on sale of short-term investments	(3,000)
Provision for bad debts			(264,000)
Changes in operating assets and liabilities:
Accounts receivable	(2,232,000)	(3,536,000)	417,000
Inventories	(3,247,000)	(489,000)	(1,612,000)
Deferred contract sales organization fees	(720,000)
Other current assets	(1,807,000)	(794,000)	(167,000)
Other assets	183,000	(266,000)	(231,000)
Accounts payable	2,974,000	3,567,000	284,000
Accrued expenses	2,123,000	426,000	1,505,000
Deferred revenue	3,662,000
Net cash used in operating activities	(70,646,000)	(25,867,000)	(17,390,000)
Cash Flows From Investing Activities:
Purchases of short-term investments	(66,088,000)
Sales and maturities of short-term investments	50,816,000	3,000,000	4,497,000
Capital expenditures	(3,550,000)	(1,023,000)	(339,000)
Intangible asset acquisition	(500,000)		(6,283,000)
Net cash provided by (used in) investing activities	(19,322,000)	1,977,000	(2,125,000)
Cash Flows From Financing Activities:
Proceeds from Deerfield debt note, net of fees	58,419,000
Proceeds from senior debt note		10,000,000	15,000,000
Prepayment of senior debt and fee	(26,063,000)
Proceeds from sale of equipment	415,000		795,000
Net proceeds from issuance of stock	13,000	18,122,000	17,350,000
Net proceeds from initial public offering, net of underwriting discounts, commissions and offering costs		75,013,000
Payments made on borrowings	(9,166,000)	(1,654,000)	(11,671,000)
Payments made to purchase treasury stock	(61,000)	(171,000)
Deferred financing costs			(563,000)
Net cash provided by financing activities	23,557,000	101,310,000	20,911,000
Increase (decrease) in cash and cash equivalents	(66,411,000)	77,420,000	1,396,000
Cash and Cash Equivalents:
Beginning	90,763,000	13,343,000	11,947,000
Ending	24,352,000	90,763,000	13,343,000
Noncash Investing and Financing Activities:
Earnout liability incurred in connection with intangible assets acquisition			589,000
Issuance of stock warrants		2,131,000	1,707,000
Exercise of Series C warrants for Series C Preferred Stock		2,322,000
Cashless exercise of Series C warrants from Series C financing in IPO closing		2,842,000
Conversion of Redeemable Preferred Stocks into Common Stock		110,776,000
Reclassification of Series C warrants issued with senior debt upon IPO closing		611,000
Preferred stock accretion		1,169,000	1,118,000
Preferred stock dividend		1,221,000	2,185,000
Supplemental Cash Flow Information:
Interest paid	$ 2,857,000	$ 2,524,000	$ 1,793,000