Nature of Business (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 1,092,325	$ 1,046,889
Net loss	45,436	29,908	$ 32,141
Net cash used in operating activities	37,619	$ 25,739	$ 26,205
Cash, cash equivalents, and investments	$ 139,800