Development Derivative Liability - Narrative (Details)	1 Months Ended	12 Months Ended
	Jan. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) payment tranche $ / shares shares
Derivative Liability
Derivative [Line Items]
Initial payment, net of common stock warrants		$ 2,100,000
Funding during the period		37,100,000
Change in fair value		12,500,000
SFJ Agreement
Derivative [Line Items]
Potential milestone payments		$ 120,000,000.0
Cost of borrowing rate		16.00%
SFJ Pharmaceuticals
Derivative [Line Items]
Cost of borrowing rate		2.50%
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | SFJ Agreement
Derivative [Line Items]
Common stock, warrants issued (in shares) | shares		2,200,000
Warrants issued (in usd per share) | $ / shares		$ 6.50
Common stock, warrants issued term		10 years
Common stock, warrants exercisable term		1 year
Number of tranches | tranche		2
Common stock, warrants value, issued		$ 7,900,000
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | SFJ Agreement | Derivative Liability
Derivative [Line Items]
Initial payment, net of common stock warrants		2,075,000
Funding during the period		37,137,000
Change in fair value		$ 12,507,000
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | SFJ Agreement | Tranche A
Derivative [Line Items]
Common stock, warrants issued (in shares) | shares		1,100,000
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | SFJ Agreement | Tranche B
Derivative [Line Items]
Common stock, warrants issued (in shares) | shares		1,100,000
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | bentracimab | SFJ Agreement
Derivative [Line Items]
Additional payment for license		$ 47,100,000
Additional payment received for license agreement		42,900,000
Initial payment received for license agreement		10,000,000.0
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | bentracimab | United States Food And Drug Administration | SFJ Agreement
Derivative [Line Items]
Additional payment for license		325,000,000.0
Initial payment for license		$ 5,000,000.0
Number of additional annual payments | payment		7
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | bentracimab | European Medicines Agency | SFJ Agreement
Derivative [Line Items]
Additional payment for license		$ 205,000,000.0
Initial payment for license		$ 5,000,000.0
Number of additional annual payments | payment		7
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | bentracimab | Pharmaceuticals And Medical Devices Agency Of Japan And National Medical Productions Administration Of China | SFJ Agreement
Derivative [Line Items]
Additional payment for license		$ 59,000,000.0
Initial payment for license		$ 1,000,000.0
Number of additional annual payments | payment		8
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | bentracimab | Maximum | SFJ Agreement
Derivative [Line Items]
Potential milestones payment receivable	$ 120,000,000.0	$ 30,000,000.0