CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net loss	$ (27,183)	$ (87,441)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,182	4,457
Stock-based compensation expense	6,762	9,676
Change in fair value of contingent consideration	1,767	734
Goodwill impairment charge		18,504
Changes in operating assets and liabilities:
Accounts receivable	4,895	(14,509)
Prepaid expenses and other assets	890	2,579
Accounts payable	(6,026)	(583)
Accrued expenses	87	13,887
Net cash used in operating activities	(17,626)	(52,696)
Cash flows from investing activities:
Purchases of property and equipment	(141)	(525)
Purchases of marketable securities	(27,139)	(89,407)
Proceeds from sales and maturities of marketable securities	30,735	117,500
Net cash provided by (used in) investing activities	3,455	27,568
Cash flows from financing activities:
Proceeds from debt financing (including warrants), net of issuance costs	10,913
Finance lease payments	(92)	(240)
Proceeds from exercise of employee stock options and the issuance of stock		3
Net cash (used in) provided by financing activities	10,821	(237)
Net decrease in cash and cash equivalents	(3,350)	(25,365)
Cash, cash equivalents and restricted cash at beginning of period	35,937	57,019
Cash, cash equivalents and restricted cash at end of period	32,587	31,654
Supplemental disclosure of non-cash investing and financing activities:
Additions to property and equipment included in accounts payable	$ 339	392
Operating lease asset recorded as a result of new accounting standard		$ 2,132