Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities:
Net loss	$ (44,315)	$ (29,218)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	2,804	3,262
Depreciation and amortization	366	694
Amortization of debt issuance costs and debt discount	506	677
Inventory write-down	2,232	0
Asset impairment charges	920	0
Change in fair value of common stock warrant liabilities	(740)	(5,504)
Change in fair value of contingent consideration	1,100	2,600
Changes in operating assets and liabilities:
Trade accounts receivable	7,893	(712)
Inventory	2,583	186
Prepaid expenses and other current assets	2,602	(2,138)
Other assets	(848)	(1,172)
Accounts payable, accrued expenses and other liabilities	150	(3,911)
Deferred revenue	(1,245)	(1,193)
Net cash used in operating activities	(25,992)	(36,429)
Investing activities:
Purchases of property and equipment	(35)	(99)
Change in restricted cash related to a previous divestiture	0	10,002
Net cash (used in) provided by investing activities	(35)	9,903
Financing activities:
Proceeds from term loan	0	2,167
Principal payments on term loan obligation	0	(3,334)
Proceeds from issuance of common stock under employee stock plans	237	141
Net cash provided by (used in) financing activities	237	(1,026)
Net decrease in cash and cash equivalents	(25,790)	(27,552)
Cash and cash equivalents, beginning of the period	91,551	155,349
Cash and cash equivalents, end of the period	$ 65,761	$ 127,797