Registration of securities issued in business combination transactions

Accounting Policies - Additional Information (Detail)

v3.7.0.1
Accounting Policies - Additional Information (Detail)
$ in Millions
3 Months Ended 4 Months Ended 12 Months Ended 18 Months Ended
Mar. 31, 2017
Apr. 24, 2015
USD ($)
Dec. 31, 2016
USD ($)
Segment
Dec. 31, 2009
USD ($)
Jun. 30, 2016
USD ($)
Accounting Policies [Line Items]          
Maturity period of liquid investments     3 months    
Maturity period of financial instruments     Greater than three months and less than one year    
Direct and indirect development costs     $ 30.0    
Revenue recognized       $ 22.0  
Number of operating segments | Segment     1    
Restricted Stock Unit [Member]          
Accounting Policies [Line Items]          
Award vesting period 4 years   4 years    
Collaborative Arrangement [Member] | Teva Pharmaceutical Industries Ltd. [Member]          
Accounting Policies [Line Items]          
Proceeds from advance reimbursement research and development   $ 27.0      
Hold-back amount and third-party expenses deducted from advanced reimbursement payment   3.8      
Hold-back amount deducted from advanced reimbursement payment   3.0      
Third-party expenses deducted from advanced reimbursement payment   $ 0.8      
Collaboration revenue         $ 23.2