Collaboration Revenue - Changes in Contract Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue - related party, Deductions	$ (27,188)	$ (15,774)
ASU 2014-09 [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue - related party, Balance at beginning of period	137,259	123,783
Deferred revenue - related party, Additions		40,393
Deferred revenue - related party, Deductions	(27,188)	(26,917)
Deferred revenue - related party, Balance at end of period	110,071	$ 137,259
Deferred revenue, Additions	15,883
Deferred revenue, Deductions	(6,215)
Deferred revenue, Balance at end of period	$ 9,668