v3.25.1
Fair value of assets and liabilities - Expected Timing Sensitivity of Level 3 Valuations (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2025
Dec. 31, 2024
6 months duration    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Increase in expected timing of a favorable outcome 6 months 6 months
Decrease in expected timing of a favorable outcome 6 months 6 months
Decrease in consolidated income and net assets due to increase in expected timing of a favorable outcome $ (196,405) $ (200,908)
Increase in consolidated income and net assets due to decrease in expected timing of a favorable outcome $ 202,711 $ 196,721
12 months duration    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Increase in expected timing of a favorable outcome 12 months 12 months
Decrease in expected timing of a favorable outcome 12 months 12 months
Decrease in consolidated income and net assets due to increase in expected timing of a favorable outcome $ (390,776) $ (396,845)
Increase in consolidated income and net assets due to decrease in expected timing of a favorable outcome $ 417,624 $ 405,926