XML 65 R43.htm IDEA: XBRL DOCUMENT v3.22.1
Investment Securities (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2022
Dec. 31, 2021
Mar. 31, 2021
Schedule of Investments [Line Items]      
Net unsettled investment purchases $ 800.0   $ 1,800.0
Transferred securities from available for sale to held to maturity 18,700.0    
Net unrealized losses, related to securities transferred to held to maturity 1,300.0    
Investment securities, allowance for credit loss 134.0 $ 133.0  
Pretax loss included in AOCI from derivatives (22.1)    
U.S. Treasury and government agencies      
Schedule of Investments [Line Items]      
Transferred securities from available for sale to held to maturity 9,200.0    
Mortgage-backed Securities Agency | Residential mortgage-backed      
Schedule of Investments [Line Items]      
Transferred securities from available for sale to held to maturity 9,500.0    
Federal National Mortgage Association Certificates and Obligations (FNMA)      
Schedule of Investments [Line Items]      
Debt securities amortized cost amount of debt securities exceeds 10 percent of shareholders equity 35,300.0    
Fair value of debt securities of a single issuer that exceeds 10 percent of shareholders equity 34,300.0    
Federal Home Loan Mortgage Corporation (FHLMC) Insured Loans      
Schedule of Investments [Line Items]      
Debt securities amortized cost amount of debt securities exceeds 10 percent of shareholders equity 28,300.0    
Fair value of debt securities of a single issuer that exceeds 10 percent of shareholders equity $ 27,200.0