XML 109 R91.htm IDEA: XBRL DOCUMENT v3.24.0.1
Fair Value (Fair Value Of Financial Assets And Liabilities Measured On A Recurring Basis) (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Risk management assets $ 23.3 $ 84.8
Available-for-sale debt securities 159.1 151.6
Total 182.4 236.4
Risk management liabilities 9.4 3.0
Total 9.4 3.0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Risk management assets 0.0 0.0
Available-for-sale debt securities 0.0 0.0
Total 0.0 0.0
Risk management liabilities 0.0 0.0
Total 0.0 0.0
Significant Other Observable Inputs (Level 2) [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Risk management assets   84.8
Available-for-sale debt securities 159.1 151.6
Total 182.4 236.4
Derivative Liability Statement Of Financial Position Extensible Enumeration Not Disclosed Flag   3.0
Risk management liabilities 9.4  
Total 9.4 3.0
Derivative Asset Statement Of Financial Position Extensible Enumeration Not Disclosed Flag 23.3  
Significant Unobservable Inputs (Level 3) [Member]    
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]    
Risk management assets 0.0 0.0
Available-for-sale debt securities 0.0 0.0
Total 0.0 0.0
Risk management liabilities 0.0 0.0
Total $ 0.0 $ 0.0