Restructuring and Other Related Costs - Restructuring and Other Reserve Activities (Details) - Restructuring Effort 2020 - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 397	$ 0
Restructuring and other related costs	974	839
Cash paid	(1,371)	(442)
Ending Balance	0	397
Severance and Other Employee Costs
Restructuring Reserve [Roll Forward]
Beginning Balance	338	0
Restructuring and other related costs	897	780
Cash paid	(1,235)	(442)
Ending Balance	0	338
Lease Termination Costs
Restructuring Reserve [Roll Forward]
Beginning Balance	59	0
Restructuring and other related costs	77	59
Cash paid	(136)	0
Ending Balance	$ 0	$ 59