Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock	APIC	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019		106,865,830
Beginning balance at Dec. 31, 2019	$ 327,271	$ 11	$ 759,322	$ (432,062)
Increase (Decrease) in Stockholders' Equity
Net loss	(10,669)			(10,669)
Stock-based compensation	6,559		6,559
Shares issued in connection with employee stock plans, net of shares withheld for employee taxes (in shares)		317,803
Shares issued in connection with employee stock plans, net of shares withheld for employee taxes	(724)		(724)
Ending balance (in shares) at Mar. 31, 2020		107,183,633
Ending balance at Mar. 31, 2020	$ 322,437	$ 11	765,157	(442,731)
Beginning balance (in shares) at Dec. 31, 2020	99,690,942	99,690,942
Beginning balance at Dec. 31, 2020	$ 382,782	$ 10	738,290	(355,518)
Increase (Decrease) in Stockholders' Equity
Net loss	(8,418)			(8,418)
Repurchase of common stock (in shares)		(1,683,692)
Repurchase of common stock	(7,829)		(7,829)
Stock-based compensation	6,732		6,732
Shares issued in connection with employee stock plans, net of shares withheld for employee taxes (in shares)		660,311
Shares issued in connection with employee stock plans, net of shares withheld for employee taxes	$ (1,075)		(1,075)
Ending balance (in shares) at Mar. 31, 2021	98,667,561	98,667,561
Ending balance at Mar. 31, 2021	$ 372,192	$ 10	$ 736,118	$ (363,936)