Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Common Stock May 17, 2019	Common Stock June 12, 2019	Common Stock March 20, 2019	Common Stock March 12, 2020	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income/(Loss)
Beginning balance at Dec. 31, 2018	$ 5,369	$ 1					$ 76,348	$ (71,020)	$ 40
Beginning balance, shares at Dec. 31, 2018		11,534,190
Net loss	(25,268)							(25,268)
Issuance of restricted common stock, shares			19,407	64,982	2,406,618
Issuance of common stock	29,628	$ 1					29,627
Issuance of common stock, shares		3,600,000
Stock-based compensation	$ 13,373						13,373
Exercise of stock options, shares	44	44
Other comprehensive income (loss)	$ 13								13
Ending balance at Jun. 30, 2019	23,115	$ 2					119,348	(96,288)	53
Ending balance, shares at Jun. 30, 2019		17,625,241
Beginning balance at Mar. 31, 2019	(1,495)	$ 1					77,848	(79,409)	65
Beginning balance, shares at Mar. 31, 2019		13,940,808
Net loss	(16,879)							(16,879)
Issuance of restricted common stock, shares			19,407	64,982
Issuance of common stock	29,628	$ 1					29,627
Issuance of common stock, shares		3,600,000
Stock-based compensation	11,873						11,873
Exercise of stock options, shares		44
Other comprehensive income (loss)	(12)								(12)
Ending balance at Jun. 30, 2019	23,115	$ 2					119,348	(96,288)	53
Ending balance, shares at Jun. 30, 2019		17,625,241
Beginning balance at Dec. 31, 2019	10,727	$ 2					140,477	(129,809)	57
Beginning balance, shares at Dec. 31, 2019		17,736,649
Net loss	(17,967)							(17,967)
Issuance of restricted common stock, shares		134,364				439,145
Forfeiture of shares of restricted common stock, shares		(134,366)				(371,329)
Stock-based compensation	12,610						12,610
Shares of restricted common stock retired in connection with vesting	(139)						(139)
Shares of restricted common stock retired in connection with vesting, shares		(41,299)
Other comprehensive income (loss)	(9)								(9)
Ending balance at Jun. 30, 2020	5,222	$ 2					152,948	(147,776)	48
Ending balance, shares at Jun. 30, 2020		17,763,164
Beginning balance at Mar. 31, 2020	2,995	$ 2					147,777	(144,839)	55
Beginning balance, shares at Mar. 31, 2020		17,763,994
Net loss	(2,937)							(2,937)
Issuance of restricted common stock, shares		134,364
Forfeiture of shares of restricted common stock, shares		(134,366)
Stock-based compensation	5,171						5,171
Shares of restricted common stock retired in connection with vesting, shares		(828)
Other comprehensive income (loss)	(7)								(7)
Ending balance at Jun. 30, 2020	$ 5,222	$ 2					$ 152,948	$ (147,776)	$ 48
Ending balance, shares at Jun. 30, 2020		17,763,164