Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.19.1
Summary of Significant Accounting Policies - Additional Information (Detail)
 12 Months Ended
Aug. 01, 2017
shares
Dec. 31, 2018
USD ($)
Segment
Dec. 31, 2017
USD ($)
Jan. 01, 2019
USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]        
Number of issued and outstanding shares of common stock converted into one issued and outstanding share of common stock | shares 11      
Number of issued and outstanding shares of common stock converted by every eleven shares of issued and outstanding common stock | shares 1      
Impairment of long lived assets | $   $ 0 $ 0  
Reportable segment | Segment   1    
ASU 2016-02 | Subsequent Event        
Organization And Summary Of Significant Accounting Policies [Line Items]        
Right-of-use asset | $       $ 4,200,000
Lease liability | $       $ 4,700,000
Leasehold Improvements | Minimum        
Organization And Summary Of Significant Accounting Policies [Line Items]        
Property and equipment, estimated useful lives   5 years    
Leasehold Improvements | Maximum        
Organization And Summary Of Significant Accounting Policies [Line Items]        
Property and equipment, estimated useful lives   7 years    
Revenue | Credit Risk        
Organization And Summary Of Significant Accounting Policies [Line Items]        
Percentage of total revenues   53.00% 56.00%  
Threshold        
Organization And Summary Of Significant Accounting Policies [Line Items]        
Reverse stock split of common stock, description 11-for-1 reverse stock split      
Reverse stock split of common stock conversion ratio 11      
Exchange ratio of company common stock shares exchanged for each share owned by private molecular stockholders | shares 7.7844      
Threshold equity holders ownership interest 34.40%      
Private Molecular equity holders ownership interest 65.60%