Income Taxes - Schedule of Income before Income Tax, German and Overseas (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Germany	$ (89,061)	$ (75,966)
Overseas	(47,540)	(25,847)
Total loss before income taxes	$ (136,601)	$ (101,813)