v3.26.1
Fair Value Measurements (Assets and Liabilities at Fair Value) (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments $ 273.2 $ 248.8
SMAs   76.2
Other investments   1,631.5
Total — fair value 1,054.6 1,707.7
Total assets 1,327.8 1,956.5
Derivative instruments 182.1 259.7
Total liabilities 182.1 259.7
Quoted prices in active markets for identical assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 0.0 0.0
SMAs   0.0
Other investments   278.1
Total — fair value 222.1 278.1
Total assets 222.1 278.1
Total liabilities 0.0 0.0
Significant other observable inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 273.2 248.8
SMAs   76.2
Other investments   0.1
Total — fair value 0.1 76.3
Total assets 273.3 325.1
Total liabilities 182.1 259.7
Significant unobservable inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 0.0 0.0
SMAs   0.0
Other investments   1,353.3
Total — fair value 832.4 1,353.3
Total assets 832.4 1,353.3
Total liabilities 0.0 0.0
Cross-currency and interest rate derivative contracts    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 257.0 240.9
Derivative instruments 168.6 248.2
Cross-currency and interest rate derivative contracts | Quoted prices in active markets for identical assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 0.0 0.0
Derivative instruments 0.0 0.0
Cross-currency and interest rate derivative contracts | Significant other observable inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 257.0 240.9
Derivative instruments 168.6 248.2
Cross-currency and interest rate derivative contracts | Significant unobservable inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 0.0 0.0
Derivative instruments 0.0 0.0
Foreign currency forward and option contracts    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 2.8 0.1
Derivative instruments 1.7 2.8
Foreign currency forward and option contracts | Quoted prices in active markets for identical assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 0.0 0.0
Derivative instruments 0.0 0.0
Foreign currency forward and option contracts | Significant other observable inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 2.8 0.1
Derivative instruments 1.7 2.8
Foreign currency forward and option contracts | Significant unobservable inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 0.0 0.0
Derivative instruments 0.0 0.0
Other    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 13.4 7.8
Derivative instruments 11.8 8.7
Other | Quoted prices in active markets for identical assets (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 0.0 0.0
Derivative instruments 0.0 0.0
Other | Significant other observable inputs (Level 2)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 13.4 7.8
Derivative instruments 11.8 8.7
Other | Significant unobservable inputs (Level 3)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total derivative instruments 0.0 0.0
Derivative instruments $ 0.0 $ 0.0