Income Taxes - Provision and Components of Net Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes
Income tax benefit	$ (1,305)	$ 691	$ 799
Domestic and foreign components of net loss
Domestic	(71,073)	(72,271)	(37,511)
Foreign	6,228	(5,607)	(2,212)
Loss before income tax (expense) benefit	$ (64,845)	$ (77,878)	$ (39,723)