XML 55 R35.htm IDEA: XBRL DOCUMENT v3.24.3
Debt (Narrative) (Details)
$ in Millions
9 Months Ended
Sep. 30, 2024
USD ($)
Sep. 30, 2023
USD ($)
Dec. 31, 2023
USD ($)
Debt Instrument [Line Items]      
Proceeds from Issuance of Long-term Debt $ 0.0 $ 100.0  
Less: current portion (414.0)   $ (0.2)
Debt Instrument, Unamortized Discount (Premium), Net (0.6)   (0.6)
Short-Term Bank Loans and Notes Payable 150.0    
Subsidiaries [Member]      
Debt Instrument [Line Items]      
Long-term Line of Credit 45.0   15.0
Proceeds from Issuance of Long-term Debt 0.0 $ 100.0  
Less: current portion (0.2)   (0.2)
Deferred Finance Costs, Net, Including Acquisition Adjustments (6.6)   (7.1)
Debt Instrument, Unamortized Discount (Premium), Net (2.3)   (2.2)
Short-Term Bank Loans and Notes Payable 150.0    
3.95% Senior Notes due 2049 [Member] | Subsidiaries [Member]      
Debt Instrument [Line Items]      
Long-term Debt, Gross $ 425.0   425.0
Debt Instrument, Interest Rate, Effective Percentage 3.95%    
Revolving Credit Facility [Member] | Subsidiaries [Member]      
Debt Instrument [Line Items]      
Debt Covenant, Total Debt to Total Capitalization Ratio, Maximum 0.67    
3.25% First Mortgage Bonds due 2040 [Member] | Subsidiaries [Member]      
Debt Instrument [Line Items]      
Long-term Debt, Gross $ 140.0   140.0
Debt Instrument, Interest Rate, Effective Percentage 3.20%    
U.S. Government note maturing in February 2061 - 4.20% [Member] | Subsidiaries [Member]      
Debt Instrument [Line Items]      
Long-term Debt, Gross     16.8
Debt instrument interest percentage 4.20%    
4.25% Tax-exempt First Mortgage Bonds due 2027 | Subsidiaries [Member]      
Debt Instrument [Line Items]      
Long-term Debt, Gross $ 100.0   100.0
Debt Instrument, Interest Rate, Effective Percentage 4.25%    
4.00% Tax-exempt First Mortgage Bonds due 2027 | Subsidiaries [Member]      
Debt Instrument [Line Items]      
Long-term Debt, Gross $ 40.0   $ 40.0
Debt Instrument, Interest Rate, Effective Percentage 4.00%