Condensed Consolidated Statements of Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Total	Convertible Senior Notes Due 2022	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 2026	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2019	$ 220,312			$ 34		$ 425,945			$ (199,920)	$ (5,747)
Beginning Balance, shares at Dec. 31, 2019				33,848,627
Issuance of common stock in connection with acquisition	30,434					30,434
Issuance of common stock in connection with acquisition, shares				301,941
Stock-based compensation	10,368					10,368
Vesting of restricted stock units and performance-based restricted stock units, shares				44,606
Restricted stock units and performance-based restricted stock units withheld to settle employee tax withholding liability	(400)					(400)
Restricted stock units and performance-based restricted stock units withheld to settle employee tax withholding liability, shares				(4,483)
Exercise of stock options	2,989					2,989
Exercise of stock options, shares				126,374
Issuance of shares under employee stock purchase plan	1,710					1,710
Issuance of shares under employee stock purchase plan, shares				30,943
Other comprehensive loss	(6,520)									(6,520)
Net loss	(25,385)								(25,385)
Balance at Mar. 31, 2020	233,508			$ 34		471,046			(225,305)	(12,267)
Ending Balance, shares at Mar. 31, 2020				34,348,008
Balance at Dec. 31, 2020	252,305			$ 35		542,776			(293,316)	2,810
Beginning Balance, shares at Dec. 31, 2020				35,449,447
Issuance of common stock in connection with acquisition	23,032					23,032
Issuance of common stock in connection with acquisition, shares				162,820
Stock-based compensation	12,770					12,770
Vesting of restricted stock units and performance-based restricted stock units	1			$ 1
Vesting of restricted stock units and performance-based restricted stock units, shares				64,304
Restricted stock units and performance-based restricted stock units withheld to settle employee tax withholding liability	(1,611)					(1,611)
Restricted stock units and performance-based restricted stock units withheld to settle employee tax withholding liability, shares				(11,649)
Exercise of stock options	$ 1,604					1,604
Exercise of stock options, shares	52,955			52,955
Issuance of shares under employee stock purchase plan	$ 2,451					2,451
Issuance of shares under employee stock purchase plan, shares				23,499
Equity component of convertible notes due 2026, net of allocated issuance costs and taxes			$ 99,000					$ 99,000
Purchase of capped call hedge for the convertible notes due 2026, including issuance costs			$ (35,124)					$ (35,124)
Equity component of settlement of convertible notes due 2022		$ 15,652			$ 2		$ 15,650
Equity component of settlement of convertible notes due 2022, shares					1,870,823
Termination and modification of capped call hedge for convertible notes due 2022		$ 10,886					$ 10,886
Other comprehensive loss	(2,597)									(2,597)
Net loss	(21,789)								(21,789)
Balance at Mar. 31, 2021	$ 356,580			$ 38		$ 671,434			$ (315,105)	$ 213
Ending Balance, shares at Mar. 31, 2021				37,612,199