Consolidated Statements of Changes in Mezzanine Equity and Stockholders’ Equity - USD ($) $ in Thousands	Total	Cumulative-effect adjustment from accounting changes	Series A Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Cumulative-effect adjustment from accounting changes	Accumulated Deficit	Accumulated Deficit Cumulative-effect adjustment from accounting changes	Accumulated Other Comprehensive Income (Loss)
Redeemable convertible preferred stock beginning balance (in shares) at Dec. 31, 2018			0
Redeemable convertible preferred stock beginning balance at Dec. 31, 2018			$ 0
Redeemable convertible preferred stock ending balance (in shares) at Dec. 31, 2019			0
Redeemable convertible preferred stock ending balance at Dec. 31, 2019			$ 0
Balance, beginning of period (in shares) at Dec. 31, 2018				90,151,341
Balance, beginning of period at Dec. 31, 2018	$ 371,938			$ 90	$ 542,829		$ (170,981)		$ 0
Increase (Decrease) in Stockholders' Equity
Issuance of common stock pursuant to employee stock purchase plan (in shares)				490,717
Issuance of common stock pursuant to employee stock purchase program	6,732				6,732
Issuance of common stock pursuant to exercise of stock options (in shares)				1,666,162
Issuance of common stock pursuant to exercise of stock options	9,570			$ 2	9,568
Issuance of common stock pursuant to settlement restricted stock units (in shares)				966,037
Issuance of common stock pursuant to settlement of restricted stock units				$ 1	(1)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units (in shares)				(272,660)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units	(5,126)				(5,126)
Stock-based compensation	29,095				29,095
Other comprehensive loss	42								42
Net loss	(80,805)						(80,805)
Balance, end of period (in shares) at Dec. 31, 2019				93,001,597
Balance, end of period at Dec. 31, 2019	$ 331,446			$ 93	583,097		(251,786)		42
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock, net (in shares)			40,000
Issuance of convertible preferred stock, net			$ 39,823
Redeemable convertible preferred stock ending balance (in shares) at Dec. 31, 2020	40,000		40,000
Redeemable convertible preferred stock ending balance at Dec. 31, 2020	$ 39,823		$ 39,823
Increase (Decrease) in Stockholders' Equity
Issuance of common stock pursuant to employee stock purchase plan (in shares)				320,609
Issuance of common stock pursuant to employee stock purchase program	8,174				8,174
Issuance of common stock pursuant to exercise of stock options (in shares)				2,011,938
Issuance of common stock pursuant to exercise of stock options	12,705			$ 2	12,703
Issuance of common stock pursuant to settlement restricted stock units (in shares)				1,490,506
Issuance of common stock pursuant to settlement of restricted stock units				$ 2	(2)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units (in shares)				(439,131)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units	(16,852)				(16,852)
Issuance of common stock in connection with repurchase of convertible senior notes (in shares)				2,056,180
Issuance of common stock in connection with repurchase of convertible senior notes	(699)			$ 2	(701)
Issuance of common stock as dividend on convertible preferred stock (in shares)				61,280
Issuance of common stock, net (in shares)				4,484,305
Gross proceeds	69,701			$ 4	69,697
Equity component of convertible senior notes, net	165,257				165,257
Stock-based compensation	39,321				39,321
Issuance of common stock in connection with conversion of convertible senior notes (in shares)				13,310
Issuance of common stock in connection with conversion of convertible senior notes	(138)				(138)
Other comprehensive loss	169								169
Net loss	$ (18,527)						(18,527)
Balance, end of period (in shares) at Dec. 31, 2020	103,000,594			103,000,594
Balance, end of period at Dec. 31, 2020	$ 590,557	$ (162,478)		$ 103	860,556	$ (170,240)	(270,313)	$ 7,762	211
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock, net (in shares)			0
Issuance of convertible preferred stock, net			$ 45
Redeemable convertible preferred stock ending balance (in shares) at Dec. 31, 2021	40,000		40,000
Redeemable convertible preferred stock ending balance at Dec. 31, 2021	$ 39,868		$ 39,868
Increase (Decrease) in Stockholders' Equity
Issuance of common stock pursuant to employee stock purchase plan (in shares)				334,248
Issuance of common stock pursuant to employee stock purchase program	$ 13,787				13,787
Issuance of common stock pursuant to exercise of stock options (in shares)	1,709,324			1,709,324
Issuance of common stock pursuant to exercise of stock options	$ 8,980			$ 2	8,978
Issuance of common stock pursuant to settlement restricted stock units (in shares)				1,559,425
Issuance of common stock pursuant to settlement of restricted stock units				$ 2	(2)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units (in shares)				(458,152)
Common stock surrendered for employees' tax liability upon settlement of restricted stock units	(27,067)			$ (1)	(27,066)
Issuance of common stock as dividend on convertible preferred stock (in shares)				122,560
Stock-based compensation	58,781				58,781
Purchases of capped calls related to convertible senior notes	(62,647)				(62,647)
Issuance of common stock in connection with conversion of convertible senior notes (in shares)				40,768
Issuance of common stock in connection with conversion of convertible senior notes	(63)				(63)
Other comprehensive loss	(385)								(385)
Net loss	$ (109,613)						(109,613)
Balance, end of period (in shares) at Dec. 31, 2021	106,308,767			106,308,767
Balance, end of period at Dec. 31, 2021	$ 309,852			$ 106	$ 682,084		$ (372,164)		$ (174)