v3.26.1
Acquisitions and Dispositions of Businesses - Narrative (Details)
$ in Millions
3 Months Ended 6 Months Ended
Oct. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
defendant
Jun. 30, 2025
USD ($)
defendant
Jun. 30, 2026
USD ($)
defendant
Jun. 30, 2025
USD ($)
defendant
Mar. 16, 2026
Jan. 01, 2025
Business Combination [Line Items]              
Completed dispositions | defendant   0   0      
Gain on disposition of business   $ 0   $ 20      
Gain from sales of businesses   $ 0 $ 0 20 $ 0    
Disposal Group, Disposed of by Sale, Not Discontinued Operations | NFP Intermediate Holdings A Corp.              
Business Combination [Line Items]              
Purchase price $ 2,300            
Disposal group, not discontinued operation, gain (loss) on disposal 1,200            
Intangible assets, net 760            
Goodwill $ 398            
Gain from sales of businesses       $ 20      
Human Capital              
Business Combination [Line Items]              
Completed dispositions | defendant     1   1    
ShoreOne Insurance Managers, Inc.              
Business Combination [Line Items]              
Percentage of capital acquired           100.00%  
Griffiths & Armour              
Business Combination [Line Items]              
Percentage of capital acquired             100.00%