Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation - Narrative (Details)

v3.19.3.a.u2
Stock-based Compensation - Narrative (Details)
1 Months Ended 12 Months Ended
Jun. 30, 2019
shares
Oct. 31, 2017
USD ($)
shares
Dec. 31, 2019
USD ($)
installment
$ / shares
shares
Dec. 31, 2018
USD ($)
$ / shares
shares
Dec. 31, 2017
USD ($)
$ / shares
Mar. 31, 2019
Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Total shares remaining available for issuance (shares) | shares 7,897,144   7,900,000        
Shares reserved for future issuance (in shares) | shares 14,000,000            
Number of shares authorized (in shares) | shares 8,100,000            
Weighted average grant date fair value (usd per share) | $ / shares     $ 10.77 $ 5.34 $ 2.51    
Aggregate intrinsic value of options exercised     $ 13,600,000 $ 7,600,000 $ 200,000    
Unrecognized compensation cost, options     $ 3,700,000        
Incentive Stock Options              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Option price as a percent of common stock     100.00%        
Non-Statutory Stock Options              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Option price as a percent of common stock     85.00%        
Stock options              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Percent of voting interests     10.00%        
Purchase price of common stock when voting percent is above minimum threshold     110.00%        
Expiration period     10 years        
Vesting period of units granted     4 years        
Volatility     55.30% 60.00% 62.20%    
Risk-free interest rate     2.40% 2.70% 2.00%    
Weighted-average remaining amortization period (years)     2 years 4 months 20 days        
Stock options | Tranche One              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Award vesting rights percentage     25.00%        
Stock options | Tranche Two              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Award vesting rights percentage     75.00%        
RSUs              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Weighted-average remaining amortization period (years)     8 months 12 days        
Weighted average grant date fair value (usd per share) | $ / shares     $ 19.19 $ 10.56 $ 4.22    
Equity instruments other than options, aggregate intrinsic value, vested     $ 4,100,000 $ 2,900,000 $ 1,300,000    
Unrecognized compensation cost, awards other than options     $ 1,100,000        
RSUs | Tranche One              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Vesting period of units granted     3 years        
Award vesting rights percentage 33.00%            
RSUs | Tranche Two              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Vesting period of units granted     4 years        
Award vesting rights percentage     25.00%        
Performance Shares              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Number of installments | installment     2        
Threshold level multiplier 0            
Estimated performance goal achievement rate     84.00%     118.00% 134.20%
Volatility     55.80% 60.30% 62.30%    
Risk-free interest rate     2.50% 2.70% 2.00%    
Weighted-average remaining amortization period (years)     9 months 18 days        
Weighted average grant date fair value (usd per share) | $ / shares     $ 11.44 $ 5.02 $ 2.54    
Unrecognized compensation cost, awards other than options     $ 900,000        
Exercises in period, intrinsic value     $ 1,300,000 $ 200,000 $ 0    
Performance Shares | Tranche One              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Award vesting rights percentage 50.00%            
Future vesting rights, percentage     50.00%        
Performance Shares | Tranche Two              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Award vesting rights percentage 50.00%            
Future vesting rights, percentage     50.00%        
RSAs              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Weighted-average remaining amortization period (years)     4 months 24 days        
Weighted average grant date fair value (usd per share) | $ / shares     $ 17.18 $ 14.35 $ 4.75    
Equity instruments other than options, aggregate intrinsic value, vested     $ 1,000,000.0 $ 2,100,000 $ 1,000,000.0    
Unrecognized compensation cost, awards other than options     $ 200,000        
Nonemployee Awards              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Vesting period of units granted   6 months          
Nonemployee services transaction, quantity of securities issued (shares) | shares   11,100 0 0      
Nonemployee services transaction, value of securities issued   $ 48,000          
Volatility   60.60%          
Risk-free interest rate   2.40%          
PSUs              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Weighted-average remaining amortization period (years)     4 months 24 days        
Weighted average grant date fair value (usd per share) | $ / shares     $ 14.98 $ 6.71 $ 4.25    
Equity instruments other than options, aggregate intrinsic value, vested     $ 3,800,000 $ 5,400,000 $ 2,700,000    
Unrecognized compensation cost, awards other than options     $ 300,000