v3.26.1
Investments - Additional Information (Details)
$ in Thousands
 1 Months Ended 3 Months Ended
Dec. 31, 2025
USD ($)
Mar. 31, 2025
USD ($)
Mar. 31, 2026
USD ($)
engine
aircraft
lease
Mar. 31, 2025
USD ($)
Mar. 31, 2025
USD ($)
engine
Mar. 31, 2025
USD ($)
airframe
Schedule of Equity Method Investments [Line Items]            
Maximum loss exposure     $ 1,300      
Currency translation adjustment balance $ 1,400   1,100      
Management and advisory fees     7,895 $ 1,963    
Technical expense     9,688 6,230    
Payment for fleet management services     700      
Management and advisory fee income     4,900      
Due from affiliates 0   229      
Unfunded capital commitments     43,400      
Capital commitments is expected funded by certain executives and employees     10,000      
Equipment Held For Operating Lease            
Schedule of Equity Method Investments [Line Items]            
Fund value 2,801,683   $ 2,760,517      
CASC Willis Engine Lease Company Limited            
Schedule of Equity Method Investments [Line Items]            
Ownership interest     50.00%      
Number of engines in lease portfolio | engine     6      
Number of assets sold | engine     0   0  
CASC Willis Engine Lease Company Limited | Equipment Held For Operating Lease            
Schedule of Equity Method Investments [Line Items]            
Fund value     $ 50,900      
Willis Mitsui And Company Engine Support Limited            
Schedule of Equity Method Investments [Line Items]            
Number of engines in lease portfolio | engine     73      
Number of aircrafts in lease portfolio | aircraft     1      
Management and advisory fees     $ 1,800 1,200    
Number of assets sold         3 1
Proceeds from sale of assets       32,200    
Gain on sale of asset       1,600    
Lessee, operating lease, number of engines subleased | engine     2      
Number of leases renewed | lease     1      
Technical expense     $ 700 $ 600    
Willis Mitsui And Company Engine Support Limited | Transaction One            
Schedule of Equity Method Investments [Line Items]            
Number of assets sold | engine     5      
Proceeds from sale of assets     $ 55,300      
Gain on sale of asset     15,300      
Willis Mitsui And Company Engine Support Limited | Equipment Held For Operating Lease            
Schedule of Equity Method Investments [Line Items]            
Fund value     $ 655,600      
Willis Global Engine Testing            
Schedule of Equity Method Investments [Line Items]            
Ownership interest   70.00%   70.00% 70.00% 70.00%
Maximum loss exposure   $ 3,900   $ 3,900 $ 3,900 $ 3,900
Committed amount   $ 30,600        
Willis Aviation Lending Warehouse I LLC            
Schedule of Equity Method Investments [Line Items]            
Number of assets sold | engine     11      
Proceeds from sale of assets     $ 87,200      
Gain on sale of asset     $ 400      
Liberty Mutual Investments            
Schedule of Equity Method Investments [Line Items]            
Committed amount $ 600,000          
Ownership interest percentage 10.00%          
Blackstone Credit And Insurance            
Schedule of Equity Method Investments [Line Items]            
Committed amount $ 1,000,000          
Ownership interest percentage 17.50%