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Stock-based awards (Details) - shares
1 Months Ended
Jun. 18, 2019
Jun. 30, 2019
Dec. 31, 2018
Share-based awards      
Number of shares remained available for grant   5,150,308 24,115,510
2018 Stock option and grant plan      
Share-based awards      
Number of shares of common stock issued 3,071,960    
Number of shares remained available for grant 107,635 2,303,982 1,839,913
Stock Options And Grant Plan 2019 [Member]      
Share-based awards      
Number of shares remained available for grant 107,635    
Number of shares initially reserved for issuance   2,572,457  
Percent of shares reserved and available for issuance automatically increase annually on January 1   4.00%  
Stock options vesting period   4 years  
2019 Employee stock purchase plan      
Share-based awards      
Number of shares initially reserved for issuance 273,869    
Percent of shares reserved and available for issuance automatically increase annually on January 1   1.00%  
Number of shares reserved and available for issuance automatically increase annually on January 1 (in shares)   410,803  
Maximum | Stock Options And Grant Plan 2019 [Member]      
Share-based awards      
Term of stock option   10 years