Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plans - Additional information (Details)

v3.24.0.1
Equity Incentive Plans - Additional information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Jun. 28, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Stock-based compensation $ 13,200,000 $ 13,400,000 $ 11,900,000    
unrecognized compensation costs $ 21,700,000 $ 13,100,000      
Total unrecognized compensation costs expected to be recognized, Period 3 years 6 months 1 year 8 months 12 days      
Vested (in shares) 632,575 686,030 620,116    
Unvested Performance Awards (in shares) 1,880,409 958,985 1,037,848 989,100  
Granted (in shares) 1,565,571 632,831 751,074    
Minimum          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Service vesting percentages 0.00%        
Maximum          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Service vesting percentages 200.00%        
Service-Vesting Awards          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Service vesting awards granted $ 22,200,000 $ 11,100,000 $ 12,100,000    
Service-Vesting Awards | Share-Based Payment Arrangement, Tranche One          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Service vesting percentages 33.33%        
Service-Vesting Awards | Share-Based Payment Arrangement, Tranches Two And Three          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Service vesting awards 2 years        
Service-Vesting Awards | Share-Based Payment Arrangement, Tranche Two          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Service vesting percentages 33.33%        
Service-Vesting Awards | Share-Based Payment Arrangement, Tranche Three          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Service vesting percentages 33.33%        
Service-Vesting Awards | Maximum          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Vesting period 7 years        
Employee Stock Option Member          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Stock-based compensation $ 105,000 76,000 37,000    
Service vesting awards granted $ 148,000 $ 166,000 $ 144,000    
Performance Vesting Award          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Service vesting awards The total compensation will be determined by the Company’s TSR relative to specified BDCs during a specified performance period. Depending on the results achieved during the specified performance period, the actual number of shares that a grant recipient receives at the end of the period may range from 0% to 200% of the target shares granted.        
Vesting period 4 years        
Vested (in shares) 0 487,409      
Distribution equivalent units (“DEUs”) were issued with a grant date fair value   $ 6,200,000      
Unvested Performance Awards (in shares) 0 0 487,409    
Performance Vesting Award | Minimum          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Disposal period after vesting 1 year        
Performance DEU          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Vested (in shares)   639,413 0    
Distribution equivalent units (“DEUs”) were issued with a grant date fair value $ 700,000        
Granted (in shares) 54,858        
Liability Classified Awards          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Stock-based compensation $ 1,400,000 $ 2,700,000      
unrecognized compensation costs $ 500,000 $ 1,900,000      
Total unrecognized compensation costs expected to be recognized, Period 3 months 18 days 1 year 3 months 18 days      
Vesting period 4 years        
Remaining max award value $ 3,100,000        
Weighted average performance conditions in liability 100.00%        
Accounts payable and accrued liabilities $ 2,600,000 $ 1,200,000      
Liability award vested $ 0 $ 7,200,000      
Other Liability Classified Awards          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Vesting period 3 years        
2018 Plan | Common Stock          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Common stock authorized (in shares) 18,700,000       9,261,229
Director Plan | Common Stock          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Common stock authorized (in shares) 300,000       300,000