Research and Development Collaborations (Details)	1 Months Ended		12 Months Ended
	Sep. 30, 2016 USD ($) program	Jun. 30, 2003 USD ($)	Dec. 31, 2021 USD ($) program product	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Feb. 29, 2020	Mar. 31, 2017 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues			$ 10,649,000	$ 10,835,000	$ 10,004,000
Cost of royalty revenues			533,000	534,000	503,000
Accounts receivable			$ 3,224,000	3,043,000
Number of programs licensed | program	4		4
Genentech, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Amount received for specified clinical development and regulatory objectives			$ 59,000,000
Percentage of royalty rate decrease		2.00%
Cost of royalty revenues			$ 500,000	500,000	500,000
Cost and expenses of percentage of aggregate royalty earned			5.00%
Accounts receivable			$ 3,200,000	3,000,000.0
Genentech, Inc. | Gross Royalty Revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues			$ 10,700,000	10,700,000	10,400,000
Genentech, Inc. | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Eligible to receive contingent cash milestone payments (up to)		$ 115,000,000
Percentage of royalty on net sales		7.50%
Genentech, Inc. | Minimum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percentage of royalty on net sales		5.00%
Aurigene Discovery Technologies Limited
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Waived payment of milestone and other payments (up to)	$ 24,500,000
Number of products required to commercialize (at least) | product			1
Aurigene Discovery Technologies Limited | Third and Fourth Programs
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Additional funding	$ 2,000,000.0
Aurigene Discovery Technologies Limited | IRAK4, PD1/VISTA,PD1/TIM3 Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Waived payment of milestone and other payments (up to)			$ 42,500,000
Aurigene Discovery Technologies Limited | Master Development and Manufacturing Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Prepaid Expense			0	100,000
Aurigene Discovery Technologies Limited | Master Development and Manufacturing Agreement | Research and development expenses
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration agreement payment			2,200,000	1,000,000.0	$ 800,000
Aurigene Discovery Technologies Limited | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty fees receivable (as a percent)						10.00%
ImmuNext
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Semi-annual maintenance fee payment			400,000
Upfront payment				$ 1,300,000
ImmuNext | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Reimbursable expenses			300,000
Option exercise fee			20,000,000.0
Potential development milestone payments			4,600,000
Potential regulatory approval milestone payments			84,300,000
Potential sales milestone payments			$ 125,000,000.0
Curis Royalty, LLC | HealthCare Royalty Partners III, L.P.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Principal loan amount							$ 45,000,000.0
Unsecured loan interest rate (percent)							9.95%