Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Convertible Senior Notes Due 2022	Convertible Senior Notes Due 2024	Convertible Senior Notes Due 2026	Common Stock	Common Stock Convertible Senior Notes Due 2022	Additional Paid-in Capital	Additional Paid-in Capital Convertible Senior Notes Due 2022	Additional Paid-in Capital Convertible Senior Notes Due 2024	Additional Paid-in Capital Convertible Senior Notes Due 2026	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2018	$ 42,158				$ 30		$ 194,866				$ (147,670)	$ (5,068)
Beginning Balance, shares at Dec. 31, 2018					29,700,192
Issuance of common stock, net of cost	138,834				$ 3		138,831
Issuance of common stock, net of cost, shares					2,645,000
Issuance of common stock in connection with acquisition	32,798						32,798
Issuance of common stock in connection with acquisition, shares					320,998
Stock-based compensation	33,989						33,989
Vesting of restricted stock units and performance-based restricted stock units, shares					275,680
Shares withheld related to net share settlement of stock awards	(4,602)						(4,602)
Shares withheld related to net share settlement of stock awards, shares					(54,312)
Exercise of stock options	17,411				$ 1		17,410
Exercise of stock options, shares					918,588
Issuance of shares under employee stock purchase plan	2,337						2,337
Issuance of shares under employee stock purchase plan, shares					42,481
Equity component of the convertible notes, net of allocated issuance costs and taxes			$ 86,133						$ 86,133
Purchase of capped call hedge for the convertible notes, including issuance costs			$ (44,948)						$ (44,948)
Equity component of repurchased convertible notes due 2022		$ (36,649)						$ (36,649)
Termination of capped call hedge for the convertible notes due 2022		5,780						5,780
Other comprehensive income (loss)	(679)											(679)
Net loss	(52,250)										(52,250)
Balance at Dec. 31, 2019	220,312				$ 34		425,945				(199,920)	(5,747)
Ending Balance, shares at Dec. 31, 2019					33,848,627
Issuance of common stock in connection with acquisition	53,193						53,193
Issuance of common stock in connection with acquisition, shares					462,224
Stock-based compensation	47,079						47,079
Vesting of restricted stock units and performance-based restricted stock units, shares					451,879
Shares withheld related to net share settlement of stock awards	(6,364)						(6,364)
Shares withheld related to net share settlement of stock awards, shares					(48,469)
Exercise of stock options	8,160				$ 1		8,159
Exercise of stock options, shares					323,838
Issuance of shares under employee stock purchase plan	3,389						3,389
Issuance of shares under employee stock purchase plan, shares					49,319
Settlement of convertible notes due 2022		11,375						11,375
Settlement of convertible notes due 2022, shares						362,029
Other comprehensive income (loss)	8,557											8,557
Net loss	(93,396)										(93,396)
Balance at Dec. 31, 2020	252,305				$ 35		542,776				(293,316)	2,810
Ending Balance, shares at Dec. 31, 2020					35,449,447
Issuance of common stock in connection with acquisition	169,541						169,541
Issuance of common stock in connection with acquisition, shares					1,311,960
Issuance of common stock for contingent consideration	7,177						7,177
Issuance of common stock for contingent consideration, shares					51,914
Stock-based compensation	44,684						44,684
Vesting of restricted stock units and performance-based restricted stock units	2				$ 2
Vesting of restricted stock units and performance-based restricted stock units, shares					573,493
Shares withheld related to net share settlement of stock awards	(10,085)						(10,085)
Shares withheld related to net share settlement of stock awards, shares					(68,832)
Exercise of stock options	$ 3,113						3,113
Exercise of stock options, shares	114,381				114,381
Issuance of shares under employee stock purchase plan	$ 4,587						4,587
Issuance of shares under employee stock purchase plan, shares					41,164
Equity component of the convertible notes, net of allocated issuance costs and taxes				$ 99,000						$ 99,000
Purchase of capped call hedge for the convertible notes, including issuance costs				$ (35,124)						$ (35,124)
Settlement of convertible notes due 2022		17,111				$ 2		17,109
Settlement of convertible notes due 2022, shares						1,916,206
Termination and modification of capped call hedge for convertible notes due 2022		$ 10,886						$ 10,886
Other comprehensive income (loss)	(5,712)											(5,712)
Net loss	(94,796)										(94,796)
Balance at Dec. 31, 2021	$ 462,689				$ 39		$ 853,664				$ (388,112)	$ (2,902)
Ending Balance, shares at Dec. 31, 2021					39,389,733