License Revenue - Summary of Changes in Balances of Receivables, Contract Assets and Contract Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Receivables and contract assets:
Accounts receivable, current and non-current, Balance at Beginning of Period	$ 58,621	$ 5,850
Accounts receivable, current and non-current, Net Additions (Deductions)	(53,397)	(626)
Accounts receivable, current and non-current, Balance at End of Period	5,224	5,224
Contract assets, Balance at Beginning of Period	250	350
Contract assets, Net Additions (Deductions)	(250)	(350)
Contract liabilities:
Deferred revenue, Net Additions (Deductions)	600	600
Deferred revenue, Balance at End of Period	$ 600	$ 600