Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net loss	$ (30,180)	$ (21,307)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	1,912	1,673
Depreciation and amortization	23	213
Amortization of debt issuance costs and debt discount	0	252
Asset impairment charges	0	813
Change in fair value of common stock warrant liabilities	(17)	(587)
Change in fair value of contingent consideration	0	600
Changes in operating assets and liabilities:
Trade accounts receivable	0	11,550
Inventory	0	(2,052)
Prepaid expenses and other assets	2,588	226
Accounts payable, accrued expenses and other liabilities	891	(2,525)
Deferred revenue	0	(273)
Net cash used in operating activities	(24,783)	(11,417)
Investing activities:
Purchases of property and equipment	(65)	(26)
Net cash used in investing activities	(65)	(26)
Financing activities:
Proceeds from issuance of common stock under equity incentive plans	3,590	0
Taxes paid related to net share settlement of equity awards	(292)	0
Net cash provided by financing activities	3,298	0
Net decrease in cash and cash equivalents	(21,550)	(11,443)
Cash and cash equivalents, beginning of the period	293,503	91,551
Cash and cash equivalents, end of the period	$ 271,953	$ 80,108