Revenue Recognition - Schedule of Changes in Contract Assets and Liabilities (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Capitalized Contract Cost [Line Items]
Total contract assets, Balance at Beginning of Period	$ 6,694
Contract assets, Addition	2,761
Contract assets, Deduction	(4,795)
Total contract assets, Balance at End of Period	4,660
Total contract liabilities, Balance at Beginning of Period	7,623
Contract liabilities, Addition	5,173
Contract liabilities, Deduction	(3,523)
Total contract liabilities, Balance at End of Period	9,273
Unbilled- collaboration and license revenue
Capitalized Contract Cost [Line Items]
Total contract assets, Balance at Beginning of Period	6,694
Contract assets, Addition	2,761
Contract assets, Deduction	(4,795)
Total contract assets, Balance at End of Period	4,660
Deferred revenue
Capitalized Contract Cost [Line Items]
Total contract liabilities, Balance at Beginning of Period	7,623
Contract liabilities, Addition	5,173
Contract liabilities, Deduction	(3,523)
Total contract liabilities, Balance at End of Period	$ 9,273