v3.26.1
BUSINESS COMBINATIONS - Narrative (Cadence) (Details)
$ in Millions
3 Months Ended
Feb. 01, 2026
USD ($)
shares
Jan. 30, 2026
USD ($)
Mar. 31, 2026
USD ($)
Rate
Dec. 31, 2025
USD ($)
Business Combination [Line Items]        
Preliminary goodwill     $ 9,527 $ 5,997
Series A Non-Cumulative Perpetual Preferred Stock | Cadence        
Business Combination [Line Items]        
Dividend Rate 5.50%      
Preferred stock, convertible, conversion ratio 0.001      
Series L Preferred Stock        
Business Combination [Line Items]        
Dividend Rate | Rate     5.50%  
Series L Preferred Stock | Cadence        
Business Combination [Line Items]        
Dividend Rate 5.50%      
Common Stock        
Business Combination [Line Items]        
Issuance of stock, acquisition (in shares) | shares 462,000,000      
Cadence        
Business Combination [Line Items]        
Share issuance ratio | shares 2.475      
Business combination, voting equity interest acquired, percentage 100.00%      
Consideration transferred $ 8,335 $ 8,300    
Preliminary goodwill 3,497      
Servicing rights and other intangible assets 1,005      
Cadence | Core deposit intangible        
Business Combination [Line Items]        
Servicing rights and other intangible assets $ 855      
Useful life 10 years