Debt (Details)	1 Months Ended	3 Months Ended	12 Months Ended
	Apr. 30, 2020 USD ($)	Dec. 31, 2021 USD ($) D $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) D $ / shares shares	Dec. 31, 2019 USD ($)	Jul. 31, 2021 $ / shares shares	Sep. 30, 2020 $ / shares shares	Oct. 31, 2019 $ / shares shares	Apr. 30, 2019 $ / shares shares	Sep. 30, 2015 USD ($)
Debt Instrument [Line Items]
Proceeds from Convertible Note, net of issuance costs				$ 278,316,000
Common Stock, Par or Stated Value Per Share | $ / shares		$ 0.0001	$ 0.0001	$ 0.0001
Issuance of common stock to Orbimed					$ 507,000
Common stock, shares issued | shares		95,140,000	95,140,000	86,223,000		5,175,000	4,791,665	5,714,286	5,263,158
Stock issued (in dollars per share) | $ / shares						$ 113		$ 35	$ 19
Stock price (in dollars per share) | $ / shares							$ 60
Carrying value		$ 280,394,000	$ 280,394,000
Debt, repayment amount				$ 79,200,000
Accrued Interest		1,078,000	1,078,000	1,078,000
Amortization of debt discount and issuance cost			1,227,000	149,000	457,000
Interest expense			8,305,000	$ 15,082,000	10,693,000
Convertible Notes
Debt Instrument [Line Items]
Aggregate principal amount	$ 287,500,000	287,500,000	$ 287,500,000
Per annum interest rate (as a percent)	2.25%		2.25%
Interest expense			$ 7,696,000
Debt instrument, term			7 years
Effective interest rate (as a percent)				2.72%
Principal amount per convertible note	$ 1,000	$ 1,000
Threshold business days | D		5
Conversion price (in dollars per share) | $ / shares				$ 38.79
Initial conversion rate				25.7785
Convertible to shares of common stock				7,411,704
Percentage of principal amount converted				100.00%
Convertible Notes | Accounting Standards Update 2020-06
Debt Instrument [Line Items]
Carrying value				$ 279,167,000
Commencing after September 30, 2020 | Convertible Notes
Debt Instrument [Line Items]
Threshold trading days | D		30
Percentage of conversion price		130.00%
5 consecutive trading day period | Convertible Notes
Debt Instrument [Line Items]
Threshold trading days | D		5
Percentage of conversion price		98.00%
Redeemable for cash on or after May 2024 | Convertible Notes
Debt Instrument [Line Items]
Threshold trading days | D				30
Percentage of conversion price				130.00%
Percentage of principal amount converted				100.00%
Level 2
Debt Instrument [Line Items]
Fair value of long-term debt		$ 715,700,000	$ 715,700,000
Minimum | Commencing after September 30, 2020 | Convertible Notes
Debt Instrument [Line Items]
Threshold trading days | D		20
Minimum | Redeemable for cash on or after May 2024 | Convertible Notes
Debt Instrument [Line Items]
Threshold trading days | D				20
Line Of Credit-UBS
Debt Instrument [Line Items]
Maximum borrowing capacity										$ 50,000,000.0
Outstanding balance		$ 49,000,000.0	49,000,000.0
Interest expense			600,000	$ 800,000	1,700,000
Interest paid			600,000	$ 800,000	$ 1,700,000
Debt, interest accrued			$ 1,100,000
Line Of Credit-UBS | LIBOR
Debt Instrument [Line Items]
Spread on interest rate (as a percent)			1.10%