Quarterly report pursuant to Section 13 or 15(d)

Restructuring Charges - Additional Information (Details)

v3.19.3
Restructuring Charges - Additional Information (Details)
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2019
USD ($)
Facility
Sep. 30, 2018
USD ($)
Jun. 30, 2018
USD ($)
Sep. 30, 2019
USD ($)
Facility
Sep. 30, 2018
USD ($)
Dec. 31, 2017
Employee
Jan. 31, 2019
Facility
Dec. 31, 2018
USD ($)
Oct. 31, 2018
Facility
Apr. 14, 2018
Facility
Nov. 21, 2017
Facility
Dec. 31, 2016
Facility
Restructuring Cost And Reserve [Line Items]                        
Number of employees terminated | Employee           62            
Operating leases, number of leased facilities | Facility             3   3 3 3  
Restructuring charges (credit)   $ 900,000     $ 900,000              
Lease-related Costs [Member]                        
Restructuring Cost And Reserve [Line Items]                        
Restructuring charges (credit) $ 0     $ 0                
Lease-related Costs [Member] | Accrued and Other Liabilities [Member]                        
Restructuring Cost And Reserve [Line Items]                        
Combined lease-related liabilities, current portion               $ 1,400,000        
Lease-related Costs [Member] | Long-Term Other Liabilities [Member]                        
Restructuring Cost And Reserve [Line Items]                        
Combined lease-related liabilities, non-current portion               $ 300,000        
Sublease Agreement Commenced on May 1,2018 [Member] | Restructuring Charges [Member]                        
Restructuring Cost And Reserve [Line Items]                        
Sublease loss     $ 600,000                  
Berkeley, California [Member]                        
Restructuring Cost And Reserve [Line Items]                        
Operating leases, number of leased facilities | Facility 2     2               2