Organization and Significant Accounting Policies - Additional Information (Detail)	1 Months Ended	3 Months Ended		6 Months Ended		120 Months Ended
	Jun. 30, 2010 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) subsidiary	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jul. 31, 2020 USD ($)	May 31, 2020 USD ($)	Apr. 30, 2020 USD ($)
Product Information [Line Items]
Number of wholly owned Irish subsidiaries | subsidiary				2
Revenue from contract with customer		$ 302,400,000	$ 183,500,000	$ 539,500,000	$ 321,900,000
Accrued interest receivables write-off threshold period		90 days		90 days		90 days
Accrued interest receivables		$ 3,700,000		$ 3,700,000		$ 3,700,000
Accrued interest receivables write-off				$ 0
B I A L | Collaborative Arrangement
Product Information [Line Items]
Milestone payment									$ 20,000,000.0
AbbVie | Collaborative Arrangement
Product Information [Line Items]
Revenue from contract with customer	$ 75,000,000.0	$ 30,000,000.0				$ 165,000,000.0
Idorsia | Collaborative Arrangement
Product Information [Line Items]
Upfront payments made								$ 45,000,000.0
Takeda | Collaborative Arrangement | Subsequent Event
Product Information [Line Items]
Upfront payments made							$ 120,000,000.0