XML 45 R28.htm IDEA: XBRL DOCUMENT v3.8.0.1
Summary of Significant Accounting Policies - Additional Information (Detail)
 1 Months Ended 12 Months Ended
Apr. 30, 2016
USD ($)
Dec. 31, 2017
USD ($)
Customer
Segment
shares
Dec. 31, 2016
USD ($)
Customer
shares
Dec. 31, 2015
USD ($)
shares
Mar. 31, 2017
USD ($)
Summary Of Significant Accounting Policy [Line Items]          
Accounts receivable written off   $ 0 $ 0 $ 0  
Charge on finished goods inventory   700,000 0 0  
Impairment losses   0      
One-time contingent regulatory milestone payment pursuant to agreement with Ipsen Group $ 8,000,000        
Finite-lived intangible assets, net $ 8,000,000        
Amortization of intangible assets   1,477,000 985,000 0  
Estimated future amortization expense, 2018   1,500,000      
Estimated future amortization expense, 2019   1,500,000      
Estimated future amortization expense, 2020   1,500,000      
Estimated future amortization expense, 2021   1,000,000      
Advertising costs   15,600,000 1,600,000    
Advertising costs capitalized as prepaid expenses   $ 0 $ 0    
Number of large customers | Customer   4 4    
Stock compensation expense related to non-employee stock options   $ 75,532,000 $ 55,265,000 $ 40,194,000  
Antidilutive securities to purchase common stock | shares   18,526,000 14,739,000 11,525,000  
Number of business segments | Segment   1      
ASU 2016-09          
Summary Of Significant Accounting Policy [Line Items]          
Increase in deferred tax assets to record unrecognized excess tax benefits         $ 36,800,000
Increase to additional paid-in capital with corresponding increase to accumulated deficit         300,000
Increase in deferred tax assets to record excess tax benefit         $ 100,000
Chief Executive Officer [Member]          
Summary Of Significant Accounting Policy [Line Items]          
Stock compensation expense related to non-employee stock options       $ 9,000,000  
Customer Concentration Risk | Sales Revenue, Product Line | Four Customers          
Summary Of Significant Accounting Policy [Line Items]          
Concentration risk, percentage   89.00% 93.00%    
Customer Concentration Risk | Accounts Receivable | Four Customers          
Summary Of Significant Accounting Policy [Line Items]          
Concentration risk, percentage   87.00% 91.00%