Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Additional Information (Details)

v3.19.3
Stock-Based Compensation - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Sep. 25, 2018
Jun. 04, 2018
May 17, 2018
Sep. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Dec. 31, 2017
Jun. 08, 2018
Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Stock-based compensation             $ 14,877 $ 5,204        
Weighted Average Remaining Life (in years)             1 year 10 months 24 days          
PWERM [Member] | IPO [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Weighted average expected rate of return             80.00%          
Discount for lack of marketability             10.00%          
OPM [Model] | IPO [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Weighted average expected rate of return             20.00%          
Discount for lack of marketability             15.00%          
2018 Stock Compensation Plan [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Common stock reserved for issuance 1,632,134 3,300,000     1,918,439   1,918,439          
Maximum annual increase of outstanding stock reserved for future issuance, Percentage 5.00%                      
2018 Employee Stock Purchase Plan (ESPP) [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Maximum annual increase of outstanding stock reserved for future issuance, Percentage             1.25%          
Number of shares available for grant under the plan         446,160   446,160          
Common stock discount rate             85.00%          
Shares issued under employee stock purchase plan, Shares             9,207          
Shares issued under employee stock purchase plan, Value             $ 37,000          
2014 Stock Option Plan [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Common stock reserved for issuance                       1,000,000
Stock Options [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Stock-based compensation         $ 500 $ 300 1,000 $ 300        
Unrecognized compensation expense for stock options issued         11,000   $ 11,000          
Weighted Average Remaining Life (in years)             8 years 11 months 4 days   9 years 5 months 4 days      
Stock Options [Member] | 2018 Stock Compensation Plan [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Authorized replacement equity awards of stock options and restricted stock units   1,901,900                    
Share-based compensation arrangement by share-based payment award, Award vesting rights   generally vest 33% on the first anniversary of the grant date with the balance vesting monthly over the remaining two years                    
Share based compensation awards expiration date       Jan. 31, 2020                
Stock Options [Member] | 2018 Stock Compensation Plan [Member] | First Anniversary [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Stock options granted under the 2018 Plan vesting percentage   33.00%   25.00%                
Stock Options [Member] | 2018 Stock Compensation Plan [Member] | Second Anniversary [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Stock options granted under the 2018 Plan vesting percentage       25.00%                
Stock Options [Member] | 2018 Stock Compensation Plan [Member] | Third Anniversary [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Stock options granted under the 2018 Plan vesting percentage       25.00%                
Stock Options [Member] | 2018 Stock Compensation Plan [Member] | Forth Anniversary [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Stock options granted under the 2018 Plan vesting percentage       25.00%                
Restricted Stock Units (RSUs) [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Unrecognized compensation expense for stock options issued         $ 11,600   $ 11,600          
Weighted-average recognized period             9 months 18 days          
Restricted Stock Units (RSUs) [Member] | 2018 Stock Compensation Plan [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Authorized replacement equity awards of stock options and restricted stock units                     1,340,832  
Unrecognized compensation cost of replacement awards   $ 17,200                    
Communicated Option Awards [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Weighted Average Remaining Life (in years)                   3 years 6 months 25 days    
Weighted-average fair value of stock options granted           $ 14.32   $ 14.00        
Maximum [Member] | 2014 Stock Option Plan [Member]                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Stock option plan expiration period     10 years