CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2021		46,880
Beginning balance at Dec. 31, 2021	$ 170,462	$ 553,902	$ (154)	$ (383,286)
Increase (Decrease) in Shareholders' Equity
Net loss	(7,091)			(7,091)
Stock-based compensation expense	9,531	$ 9,531
Stock option exercises (in shares)		125
Stock option exercises	1,155	$ 1,155
Shares issued under the Employee Stock Purchase Plan (in shares)		9
Shares issued under the Employee Stock Purchase Plan	310	$ 310
Issuance of stock for restricted stock unit vesting (in shares)		108
Restricted stock withheld for employee tax remittance (in shares)		(41)
Restricted stock withheld for employee tax remittance	(1,423)	$ (1,423)
Unrealized gain (loss) on investment	(459)		(459)
Ending balance (in shares) at Mar. 31, 2022		47,081
Ending balance at Mar. 31, 2022	172,485	$ 563,475	(613)	(390,377)
Beginning balance (in shares) at Dec. 31, 2021		46,880
Beginning balance at Dec. 31, 2021	170,462	$ 553,902	(154)	(383,286)
Increase (Decrease) in Shareholders' Equity
Net loss	(22,631)
Unrealized gain (loss) on investment	(992)
Ending balance (in shares) at Sep. 30, 2022		47,201
Ending balance at Sep. 30, 2022	177,837	$ 584,900	(1,146)	(405,917)
Beginning balance (in shares) at Mar. 31, 2022		47,081
Beginning balance at Mar. 31, 2022	172,485	$ 563,475	(613)	(390,377)
Increase (Decrease) in Shareholders' Equity
Net loss	(8,963)			(8,963)
Stock-based compensation expense	10,808	$ 10,808
Stock option exercises (in shares)		32
Stock option exercises	428	$ 428
Shares issued under the Employee Stock Purchase Plan (in shares)		10
Shares issued under the Employee Stock Purchase Plan	318	$ 318
Issuance of stock for restricted stock unit vesting (in shares)		19
Restricted stock withheld for employee tax remittance (in shares)		(1)
Restricted stock withheld for employee tax remittance	(18)	$ (18)
Unrealized gain (loss) on investment	(242)		(242)
Ending balance (in shares) at Jun. 30, 2022		47,141
Ending balance at Jun. 30, 2022	174,816	$ 575,011	(855)	(399,340)
Increase (Decrease) in Shareholders' Equity
Net loss	(6,577)			(6,577)
Stock-based compensation expense	9,104	$ 9,104
Stock option exercises (in shares)		41
Stock option exercises	498	$ 498
Shares issued under the Employee Stock Purchase Plan (in shares)		15
Shares issued under the Employee Stock Purchase Plan	331	$ 331
Issuance of stock for restricted stock unit vesting (in shares)		6
Restricted stock withheld for employee tax remittance (in shares)		(2)
Restricted stock withheld for employee tax remittance	(44)	$ (44)
Unrealized gain (loss) on investment	(291)		(291)
Ending balance (in shares) at Sep. 30, 2022		47,201
Ending balance at Sep. 30, 2022	$ 177,837	$ 584,900	(1,146)	(405,917)
Beginning balance (in shares) at Dec. 31, 2022	47,253	47,253
Beginning balance at Dec. 31, 2022	$ 192,272	$ 593,245	(978)	(399,995)
Increase (Decrease) in Shareholders' Equity
Net loss	(7,495)			(7,495)
Stock-based compensation expense	8,731	$ 8,731
Stock option exercises (in shares)		132
Stock option exercises	2,009	$ 2,009
Shares issued under the Employee Stock Purchase Plan (in shares)		11
Shares issued under the Employee Stock Purchase Plan	216	$ 216
Issuance of stock for restricted stock unit vesting (in shares)		183
Restricted stock withheld for employee tax remittance (in shares)		(72)
Restricted stock withheld for employee tax remittance	(2,097)	$ (2,097)
Unrealized gain (loss) on investment	342		342
Ending balance (in shares) at Mar. 31, 2023		47,507
Ending balance at Mar. 31, 2023	$ 193,978	$ 602,104	(636)	(407,490)
Beginning balance (in shares) at Dec. 31, 2022	47,253	47,253
Beginning balance at Dec. 31, 2022	$ 192,272	$ 593,245	(978)	(399,995)
Increase (Decrease) in Shareholders' Equity
Net loss	(16,175)
Unrealized gain (loss) on investment	$ 515
Ending balance (in shares) at Sep. 30, 2023	47,684	47,684
Ending balance at Sep. 30, 2023	$ 204,380	$ 621,013	(463)	(416,170)
Beginning balance (in shares) at Mar. 31, 2023		47,507
Beginning balance at Mar. 31, 2023	193,978	$ 602,104	(636)	(407,490)
Increase (Decrease) in Shareholders' Equity
Net loss	(5,020)			(5,020)
Stock-based compensation expense	8,761	$ 8,761
Stock option exercises (in shares)		68
Stock option exercises	889	$ 889
Shares issued under the Employee Stock Purchase Plan (in shares)		18
Shares issued under the Employee Stock Purchase Plan	384	$ 384
Issuance of stock for restricted stock unit vesting (in shares)		26
Restricted stock withheld for employee tax remittance (in shares)		(3)
Restricted stock withheld for employee tax remittance	(79)	$ (79)
Unrealized gain (loss) on investment	15		15
Ending balance (in shares) at Jun. 30, 2023		47,616
Ending balance at Jun. 30, 2023	198,928	$ 612,059	(621)	(412,510)
Increase (Decrease) in Shareholders' Equity
Net loss	(3,660)			(3,660)
Stock-based compensation expense	7,924	$ 7,924
Stock option exercises (in shares)		50
Stock option exercises	787	$ 787
Shares issued under the Employee Stock Purchase Plan (in shares)		13
Shares issued under the Employee Stock Purchase Plan	329	$ 329
Issuance of stock for restricted stock unit vesting (in shares)		8
Restricted stock withheld for employee tax remittance (in shares)		(3)
Restricted stock withheld for employee tax remittance	(86)	$ (86)
Unrealized gain (loss) on investment	$ 158		158
Ending balance (in shares) at Sep. 30, 2023	47,684	47,684
Ending balance at Sep. 30, 2023	$ 204,380	$ 621,013	$ (463)	$ (416,170)