Collaborative arrangements and strategic partnerships - Changes in Balances of Company's Receivables and Contract Liabilities (Detail) - Bristol-Myers Squibb $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($)
Receivables
Balance at beginning of period	$ 400
Additions	12,661
Deductions	(400)
Balance at end of period	12,661
Contract liabilities:
Balance at beginning of period	26,582
Additions	0
Deductions	(820)
Balance at end of period	$ 25,762