XML 49 R38.htm IDEA: XBRL DOCUMENT v3.19.1
Leases - Additional Information (Detail)
$ in Thousands
 3 Months Ended
Mar. 31, 2019
USD ($)
Mar. 31, 2018
USD ($)
Dec. 31, 2018
USD ($)
ft²
Dec. 31, 2017
USD ($)
Lessee Lease Description [Line Items]        
Operating lease, description The Company leases facilities and certain equipment under noncancelable operating leases with remaining lease terms of 1 year to 7 years, one of which includes an option to extend the lease for one five-year term.      
Operating lease, option to extend true      
Operating lease, options to extend one of which includes an option to extend the lease for one five-year term.      
Operating lease, renewal term 5 years      
Operating lease, cost $ 1,300 $ 1,000    
Cash paid for the amount of lease liabilities, included in operating activities $ 1,100      
weighted average remaining lease term 4 years 8 months 12 days      
Weighted average discount rate 8.00%      
Restricted cash $ 4,787 $ 2,825 $ 4,826 $ 2,475
Corporate Office Space Lease Agreement        
Lessee Lease Description [Line Items]        
Operating leases arrangement term     10 years 9 months  
Corporate Office Space Lease Agreement | Letter of Credit        
Lessee Lease Description [Line Items]        
Restricted cash $ 2,200      
California | Corporate Office Space Lease Agreement        
Lessee Lease Description [Line Items]        
Office space leases in square feet | ft²     67,020  
Minimum lease payment amount     $ 53,700  
California | Corporate Office Space Lease Agreement        
Lessee Lease Description [Line Items]        
Lease commencement period first half of fiscal year 2020      
Minimum [Member]        
Lessee Lease Description [Line Items]        
Operating lease remaining lease term 1 year      
Maximum        
Lessee Lease Description [Line Items]        
Operating lease remaining lease term 7 years