CONDENSED CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ EQUITY (DEFICIT) - USD ($) $ in Thousands	Common Stock Common stock	Common Stock Class A common stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Convertible preferred stock	Total
Balance at the beginning of the period at Dec. 31, 2018						$ 104,774
Balance at the beginning of the period (in shares) at Dec. 31, 2018						1,323,506
Increase (Decrease) in Temporary Equity
Issuance of preferred stock, net of issuance costs						$ 37,274
Issuance of preferred stock, net of issuance costs (in shares)						257,000
Balance at the end of the period at Mar. 31, 2019						$ 142,048
Balance at the end of the period (in shares) at Mar. 31, 2019						1,580,506	1,580,506
Balance at the beginning of the period at Dec. 31, 2018	$ 0		$ 3,327	$ (3,720)	$ (59,982)		$ (60,375)
Balance at the beginning of the period (in shares) at Dec. 31, 2018	1,006,595
Increase (Decrease) in Stockholders' Equity
Foreign currency translation adjustment, net of tax				(736)			(736)
Stock-based compensation expense			383				383
Net loss					(9,329)		(9,329)
Balance at the end of the period at Mar. 31, 2019	$ 0		3,710	(4,456)	(69,311)		(70,057)
Balance at the end of the period (in shares) at Mar. 31, 2019	1,006,595
Balance at the beginning of the period at Dec. 31, 2018						$ 104,774
Balance at the beginning of the period (in shares) at Dec. 31, 2018						1,323,506
Balance at the beginning of the period at Dec. 31, 2018	$ 0		3,327	(3,720)	(59,982)		(60,375)
Balance at the beginning of the period (in shares) at Dec. 31, 2018	1,006,595
Increase (Decrease) in Stockholders' Equity
Net loss							(43,000)
Balance at the end of the period at Dec. 31, 2019	$ 3	$ 0	225,568	(4,653)	(103,019)		117,899
Balance at the end of the period (in shares) at Dec. 31, 2019	21,746,392	3,819,732
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock options	$ 0		8				$ 8
Issuance of common stock upon exercise of stock options (in shares)	78,598						78,598
Foreign currency translation adjustment, net of tax				(93)			$ (93)
Stock-based compensation expense			2,094				2,094
Net loss					(10,926)		(10,926)
Balance at the end of the period at Mar. 31, 2020	$ 3	$ 0	$ 227,670	$ (4,746)	$ (113,945)		$ 108,982
Balance at the end of the period (in shares) at Mar. 31, 2020	21,824,990	3,819,732