v3.25.4
Fair Value of Financial Instruments - Carrying Amounts and Fair Values of Debt Obligations (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Mar. 31, 2025
Carrying Amount    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations $ 5,366.0 $ 5,630.4
Carrying Amount | Commercial Paper    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 1,103.8 174.9
Carrying Amount | 4.250% 2025 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 0.0 1,198.5
Carrying Amount | 4.900% 2028 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 996.2 995.0
Carrying Amount | 5.050% 2029 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 995.2 993.9
Carrying Amount | 5.050% 2030 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 995.0 994.2
Carrying Amount | 2017 Senior Convertible Debt | Senior subordinated convertible debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 37.8 37.9
Carrying Amount | 2024 Senior Convertible Debt | Senior subordinated convertible debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 1,238.0 1,236.0
Fair Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 5,456.5 5,608.2
Fair Value | Commercial Paper    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 1,106.0 175.0
Fair Value | 4.250% 2025 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 0.0 1,196.9
Fair Value | 4.900% 2028 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 1,014.2 1,002.5
Fair Value | 5.050% 2029 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 1,020.1 1,005.8
Fair Value | 5.050% 2030 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 1,021.2 996.9
Fair Value | 2017 Senior Convertible Debt | Senior subordinated convertible debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 67.5 57.7
Fair Value | 2024 Senior Convertible Debt | Senior subordinated convertible debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations $ 1,227.5 $ 1,173.4