Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect of Accounting Change [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member] Cumulative Effect of Accounting Change [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member] Cumulative Effect of Accounting Change [Member]
Balance at Dec. 31, 2020	$ 761,759	$ (96,792)	$ 8	$ 3,609,877	$ (156,953)	$ 3	$ (2,848,129)	$ 60,161
Balance (in shares) at Dec. 31, 2020			79,374
Exercise of options for common stock	4,683			4,683
Exercise of options for common stock, shares			108
Vest of restricted stock units/awards			204
Issuance of common stock under employee stock purchase plan	4,543			4,543
Issuance of common stock under employee stock purchase plan, shares			62
Stock-based compensation	28,508			28,508
Unrealized losses from available-for-sale securities, net of tax	(6)					(6)
Net loss	(167,250)						(167,250)
Balance at Mar. 31, 2021	535,445		$ 8	3,490,658		(3)	(2,955,218)
Balance (in shares) at Mar. 31, 2021			79,748
Balance at Dec. 31, 2020	761,759	$ (96,792)	$ 8	3,609,877	$ (156,953)	3	(2,848,129)	$ 60,161
Balance (in shares) at Dec. 31, 2020			79,374
Purchase Of Capped Call Share Options For 2027 Notes	0
Partial settlement of capped call share options for 2024 Notes	0
Net loss	(296,799)
Balance at Sep. 30, 2021	469,528		$ 8	3,554,307		(20)	(3,084,767)
Balance (in shares) at Sep. 30, 2021			79,959
Balance at Mar. 31, 2021	535,445		$ 8	3,490,658		(3)	(2,955,218)
Balance (in shares) at Mar. 31, 2021			79,748
Exercise of options for common stock	3,526			3,526
Exercise of options for common stock, shares			72
Vest of restricted stock units/awards			28
Shares withheld for taxes	(1,432)			(1,432)
Shares withheld for taxes, shares			(18)
Stock-based compensation	28,969			28,969
Unrealized losses from available-for-sale securities, net of tax	5					5
Net loss	(81,405)						(81,405)
Balance at Jun. 30, 2021	485,108		$ 8	3,521,721		2	(3,036,623)
Balance (in shares) at Jun. 30, 2021			79,830
Exercise of options for common stock	2,606			2,606
Exercise of options for common stock, shares			52
Vest of restricted stock units/awards			27
Issuance of common stock under employee stock purchase plan	3,296			3,296
Issuance of common stock under employee stock purchase plan, shares			50
Stock-based compensation	26,684			26,684
Unrealized losses from available-for-sale securities, net of tax	(22)					(22)
Net loss	(48,144)						(48,144)
Balance at Sep. 30, 2021	469,528		$ 8	3,554,307		(20)	(3,084,767)
Balance (in shares) at Sep. 30, 2021			79,959
Balance at Dec. 31, 2021	928,009		$ 9	4,134,768		(20)	(3,206,748)
Balance (in shares) at Dec. 31, 2021			87,127
Exercise of options for common stock	997			997
Exercise of options for common stock, shares			18
Vest of restricted stock units/awards			289
Issuance of common stock under employee stock purchase plan	3,993			3,993
Issuance of common stock under employee stock purchase plan, shares			62
Stock-based compensation	29,198			29,198
Unrealized losses from available-for-sale securities, net of tax	(286)					(286)
Net loss	(105,025)						(105,025)
Balance at Mar. 31, 2022	856,886		$ 9	4,168,956		(306)	(3,311,773)
Balance (in shares) at Mar. 31, 2022			87,496
Balance at Dec. 31, 2021	928,009		$ 9	4,134,768		(20)	(3,206,748)
Balance (in shares) at Dec. 31, 2021			87,127
Purchase Of Capped Call Share Options For 2027 Notes	127,305
Partial settlement of capped call share options for 2024 Notes	26,317
Net loss	(594,244)
Balance at Sep. 30, 2022	430,840		$ 9	4,235,028		(3,205)	(3,800,992)
Balance (in shares) at Sep. 30, 2022			87,766
Balance at Mar. 31, 2022	856,886		$ 9	4,168,956		(306)	(3,311,773)
Balance (in shares) at Mar. 31, 2022			87,496
Exercise of options for common stock	339			339
Exercise of options for common stock, shares			11
Vest of restricted stock units/awards			28
Stock-based compensation	102,892			102,892
Unrealized losses from available-for-sale securities, net of tax	(2,179)					(2,179)
Net loss	(231,481)						(231,481)
Balance at Jun. 30, 2022	726,457		$ 9	4,272,187		(2,485)	(3,543,254)
Balance (in shares) at Jun. 30, 2022			87,535
Exercise of options for common stock	9,934			9,934
Exercise of options for common stock, shares			144
Vest of restricted stock units/awards			33
Purchase Of Capped Call Share Options For 2027 Notes	(127,305)			(127,305)
Partial settlement of capped call share options for 2024 Notes	26,317			26,317
Issuance of common stock under employee stock purchase plan	3,477			3,477
Issuance of common stock under employee stock purchase plan, shares			54
Stock-based compensation	50,418			50,418
Unrealized losses from available-for-sale securities, net of tax	(720)					(720)
Net loss	(257,738)						(257,738)
Balance at Sep. 30, 2022	$ 430,840		$ 9	$ 4,235,028		$ (3,205)	$ (3,800,992)
Balance (in shares) at Sep. 30, 2022			87,766