Quarterly report pursuant to Section 13 or 15(d)

Collaboration Agreement - Additional Information (Detail)

v3.7.0.1
Collaboration Agreement - Additional Information (Detail) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended 4 Months Ended 6 Months Ended 18 Months Ended
Apr. 24, 2015
Aug. 31, 2016
Jun. 30, 2016
Apr. 24, 2015
Jun. 30, 2016
Jun. 30, 2016
May 14, 2015
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]              
Collaboration revenue recognized     $ 2,122   $ 5,062    
Ionis Pharmaceuticals Inc. [Member]              
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]              
Litigation settlement, upfront payment   $ 1,400          
Royalty payment percentage   5.00%          
Sale, license or other transaction payment percentage   50.00%          
Ionis Pharmaceuticals Inc. [Member] | Maximum [Member]              
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]              
Litigation settlement, success based payment   $ 5,000          
Collaborative Arrangement [Member] | Teva Pharmaceutical Industries Ltd. [Member]              
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]              
Proceeds from advance reimbursement research and development       $ 27,000      
Hold-back amount and third-party expenses deducted from advanced reimbursement payment $ 3,800     3,800      
Hold-back amount deducted from advanced reimbursement payment 3,000     3,000      
Third-party expenses deducted from advanced reimbursement payment       $ 800      
Collaboration revenue recognized           $ 23,200  
Collaborative Arrangement [Member] | Ionis Pharmaceuticals Inc. [Member]              
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]              
Proceeds from advance reimbursement research and development, net amount $ 23,200            
Hold-back amount, requested payment percentage             30.00%