Subsequent Event	3 Months Ended
	Mar. 31, 2022
Subsequent Events [Abstract]
Subsequent Event	Subsequent EventAs discussed in Note 1, on April 25, 2022, we announced our Reorganization and Restructuring Plans, pursuant to which we are prioritizing key research and development efforts and reducing our workforce by approximately 70% from approximately 735 to approximately 225 employees. We will recognize all costs of the Reorganization and Restructuring Plans, including severance and benefits for employees laid off and employee compensation and third-party costs for the wind down of the bempegaldesleukin program, net of BMS’ reimbursement of our costs, in the restructuring, impairment and other costs of terminated program line in our Condensed Consolidated Statement of Operations. We expect to recognize approximately $30.0 to $35.0 million for severance and related benefits for employees laid off under the Reorganization and Restructuring Plans, primarily in the three months ending June 30, 2022