Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Total
Balance at Dec. 31, 2020	$ 9	$ 1,411,286	$ 4,259	$ (929,318)	$ 486,236
Balance (in shares) at Dec. 31, 2020	86,223
Issuance of common stock upon exercise of stock options		4,570			4,570
Issuance of common stock upon exercise of stock options (in shares)	575
Vesting of restricted stock units (in shares)	632
Stock based compensation		23,232			23,232
Unrealized loss on available-for sale securities			(1,062)		(1,062)
Cumulative-effect adjustment upon adoption of ASU 2020-06		(82,876)		6,198	(76,678)
Net loss				(63,853)	(63,853)
Balance at Mar. 31, 2021	$ 9	1,356,212	3,197	(986,973)	372,445
Balance (in shares) at Mar. 31, 2021	87,430
Balance at Dec. 31, 2021	$ 10	2,050,417	(2,287)	(1,394,836)	$ 653,304
Balance (in shares) at Dec. 31, 2021	95,140				95,140
Issuance of common stock upon exercise of stock options		4,156			$ 4,156
Issuance of common stock upon exercise of stock options (in shares)	631
Vesting of restricted stock units (in shares)	488
Stock based compensation		35,087			35,087
Unrealized loss on available-for sale securities			(11,617)		(11,617)
Net loss				(138,595)	(138,595)
Balance at Mar. 31, 2022	$ 10	$ 2,089,660	$ (13,904)	$ (1,533,431)	$ 542,335
Balance (in shares) at Mar. 31, 2022	96,259				96,259