Sale of Future Royalties - Additional Information (Details)		1 Months Ended			3 Months Ended
	Nov. 04, 2019 USD ($) Tranche $ / shares shares	Nov. 30, 2020 USD ($)	Feb. 29, 2020 USD ($) shares	Nov. 30, 2019 USD ($) $ / shares shares	Mar. 31, 2022 USD ($) shares	Mar. 31, 2021 USD ($)	Dec. 31, 2021 shares	Nov. 03, 2020 USD ($)	Jun. 30, 2020 USD ($)
Line Of Credit Facility [Line Items]
Common stock, shares issued | shares					164,868,000		106,098,000
Proceeds from issuance of common stock, net of commissions					$ 82,257,000	$ 0
Royalty Purchase Agreement [Member]
Line Of Credit Facility [Line Items]
Proceeds from sale of future royalties					12,601,000
Non cash royalty revenue					(71,000)
Non cash interest expense					$ 400,000	500,000
RPI and Affiliates [Member]
Line Of Credit Facility [Line Items]
Percentage of ownership interest related parties					19.30%		8.60%
Tazemetostat [Member] | Royalty Purchase Agreement [Member]
Line Of Credit Facility [Line Items]
Non cash royalty revenue					$ 40,000.0	$ 0
RPI Purchase Agreement [Member]
Line Of Credit Facility [Line Items]
Common stock, shares issued | shares	6,666,667
Warrants To Exercise Common Stock | $ / shares	$ 20.00			$ 20.00
Proceed from agreement	$ 100,000,000.0
Obligation to purchase common stock	50,000,000.0
Shares option to sell exercised by underwriters | shares			2,500,000
Proceeds from issuance of common stock, net of commissions			$ 50,000,000.0
Proceeds from sale of future royalties					$ 12,600,000
Effective annual interest Rate					9.01%
RPI Purchase Agreement [Member] | RPI and Affiliates [Member]
Line Of Credit Facility [Line Items]
Payments for Royalties					9.20%
RPI Purchase Agreement [Member] | Achievement of Specified Annual Net Sales [Member]
Line Of Credit Facility [Line Items]
Potential milestone payments	$ 1,500,000,000
Maximum [Member] | RPI Purchase Agreement [Member]
Line Of Credit Facility [Line Items]
Warrants to purchase shares of common stock | shares	2,500,000			2,500,000
Obligation to purchase share price | $ / shares	$ 20.00
Loan Agreement [Member] | RPI Purchase Agreement [Member]
Line Of Credit Facility [Line Items]
Transaction costs					$ 2,000,000.0
Loan Agreement [Member]
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 70,000,000.0
Percentage of commitment fee paid		2.00%		2.00%
Number of tranches | Tranche	3
Aggregate principal amount	$ 70,000,000.0
Commitment fee		$ 150,000,000.0		$ 70,000,000.0
Loan Agreement [Member] | RPI Purchase Agreement [Member]
Line Of Credit Facility [Line Items]
Common stock, shares issued | shares					79,000,000.0
Warrants to purchase shares of common stock | shares					8,400,000
Proceed from agreement					$ 125,000,000.0
Proceeds from sale of future royalties					12,600,000
Loan Agreement [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Right to request for additional loan amount	$ 300,000,000.0
First Tranche [Member] | Loan Agreement [Member]
Line Of Credit Facility [Line Items]
Aggregate principal amount									$ 25,000,000.0
First Tranche [Member] | Loan Agreement [Member] | RPI Purchase Agreement [Member]
Line Of Credit Facility [Line Items]
Aggregate principal amount					$ 25,000,000.0
Second Tranche [Member] | Loan Agreement [Member]
Line Of Credit Facility [Line Items]
Aggregate principal amount									25,000,000.0
Third Tranche [Member] | Loan Agreement [Member]
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity									$ 20,000,000.0
Fourth Tranche [Member] | Amended And Restated Loan Agreement [Member]
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity								$ 150,000,000.0
Tranche Term Loan [Member]
Line Of Credit Facility [Line Items]
Interest rate of loan								7.75%
Tranche Term Loan [Member] | Interest Rate Floor [Member]
Line Of Credit Facility [Line Items]
Interest rate of loan								2.00%