CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Cash Flows from Operating Activities:
Net income (loss)	$ (26,344)	$ 41,564	$ (54,335)	$ (6,480)	$ 15,220	$ (60,815)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation					61	107
Share-based compensation					898	682
Change in fair value of contingent consideration	18,480		44,000		(35,220)	43,000
Changes in operating assets and liabilities:
Prepaid expenses and other assets					2,719	(1,487)
Accounts payable					(628)	809
Accrued expenses and other liabilities					(1,376)	961
Net Cash Used in Operating Activities					(18,326)	(16,743)	$ (37,500)
Cash Flows from Investing Activities:
Net Cash Used in Investing Activities					(8)	(43)
Cash Flows from Financing Activities:
Proceeds from issuance of common stock under ATM Offering, net of issuance costs					7,953	0
Proceeds from sales of common stock under 2014 ESPP					1	7
Proceeds from exercises of stock options					0	45
Proceeds from the issuance of common stock and common stock warrants, net of issuance costs					0	27,809
Proceeds from the exercise of common stock warrants					0	3,434
Net Cash Provided by Financing Activities					7,954	31,295
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash					(10,380)	14,509
Cash, Cash Equivalents and Restricted Cash - Beginning of Period		$ 48,141		$ 50,442	48,141	50,442	50,442
Cash, Cash Equivalents and Restricted Cash - End of Period	37,761		64,951		37,761	64,951	$ 48,141
Supplemental disclosure of non-cash activities
Right-of-use assets related to the adoption of ASC 842					0	236
Cash paid for amounts included in the measurement of lease liabilities					75	76
Fixed assets included in Accrued Expenses					0	119
Deemed dividend on adjustment of exercise price on certain warrants	$ 147		$ 0		$ 147	$ 0