Annual report pursuant to Section 13 and 15(d)

Restructuring Charges - Additional Information (Details)

v3.10.0.1
Restructuring Charges - Additional Information (Details)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 19, 2016
Employee
Dec. 31, 2018
USD ($)
Sep. 30, 2018
USD ($)
Jun. 30, 2018
USD ($)
Dec. 31, 2017
USD ($)
Sep. 30, 2017
USD ($)
Jun. 30, 2017
USD ($)
Mar. 31, 2017
USD ($)
Dec. 31, 2018
USD ($)
Subtenant
Dec. 31, 2017
USD ($)
Employee
Restructuring Cost And Reserve [Line Items]                    
Restructuring charges (credit)   $ 543 $ 909 $ 459 $ (4) $ (29) $ 1,460 $ 2,020    
Operating leases, number of subtenants | Subtenant                 3  
Lease-related Costs [Member]                    
Restructuring Cost And Reserve [Line Items]                    
Restructuring charges (credit)                 $ 1,300  
Restructuring liability   1,400             1,400  
Reversal of deferred rent liability   700             700  
Lease-related Costs [Member] | Accrued and Other Liabilities [Member]                    
Restructuring Cost And Reserve [Line Items]                    
Combined lease-related liabilities, current portion   1,400             1,400  
Lease-related Costs [Member] | Other Liabilities Non-current [Member]                    
Restructuring Cost And Reserve [Line Items]                    
Combined lease-related liabilities, non-current portion   $ 300             $ 300  
2016 Restructuring [Member]                    
Restructuring Cost And Reserve [Line Items]                    
Number of employees terminated | Employee 57                  
2017 Restructuring [Member]                    
Restructuring Cost And Reserve [Line Items]                    
Number of employees terminated | Employee                   5
2017 and 2016 Restructuring [Member] | Severance, Other Termination Benefits and Outplacement Services [Member]                    
Restructuring Cost And Reserve [Line Items]                    
Restructuring charges (credit)                   $ 3,400