Collaboration and License Agreements - Schedule of Changes in Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Contract assets
Contract assets, beginning balance			$ 8,952
Additions			102,504
Deductions			(92,467)
Contract assets, ending balance	$ 18,989		18,989
Contract liabilities
Additions	0	$ 4,404	61,513	$ 28,823
Collaboration receivable – related party
Contract assets
Contract assets, beginning balance			1,539
Additions			4,228
Deductions			(4,693)
Contract assets, ending balance	1,074		1,074
Unbilled receivable - related party, net of current portions
Contract assets
Contract assets, beginning balance			0
Additions			1,606
Deductions			(346)
Contract assets, ending balance	1,260		1,260
Royalty receivable – related party
Contract assets
Contract assets, beginning balance			2,900
Additions			5,015
Deductions			(7,915)
Contract assets, ending balance	0		0
Deferred revenue – related party, current and net of current portions
Contract liabilities
Contract liabilities, beginning balance			61,513
Additions			2,421
Deductions			(63,934)
Contract liabilities, ending balance	$ 0		$ 0