Financial Commitments & Contingencies and Key License Agreements - Operating Lease Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Operating lease right-of-use assets - non-current	$ 2,505	$ 2,247
Operating lease liabilities - current	1,282	1,544
Operating lease liabilities - non-current	1,452	883
Total operating lease liabilities	$ 2,734	$ 2,427
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accounts payable and other accrued liabilities	Accounts payable and other accrued liabilities
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other long-term liabilities	Other long-term liabilities
Office and research facilities
Property, Plant and Equipment [Line Items]
Operating lease right-of-use assets - non-current	$ 2,100	$ 1,900
Office equipment
Property, Plant and Equipment [Line Items]
Operating lease right-of-use assets - non-current	$ 400	$ 300