v3.26.1
Fair Value of Financial Instruments (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Mar. 31, 2026
Carrying Amount    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations $ 5,361.3 $ 5,496.4
Carrying Amount | Commercial paper    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 210.6 348.5
Carrying Amount | 4.900% 2028 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 997.1 996.7
Carrying Amount | 5.050% 2029 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 995.8 995.5
Carrying Amount | 5.050% 2030 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 995.6 995.3
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 37.9 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 1,239.3 1,238.6
Carrying Amount | 2026 Senior Convertible Debt | Senior subordinated convertible debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 885.0 883.9
Fair Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 5,744.5 5,559.0
Fair Value | Commercial paper    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 211.0 349.0
Fair Value | 4.900% 2028 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 1,005.0 1,006.0
Fair Value | 5.050% 2029 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 1,008.4 1,013.6
Fair Value | 5.050% 2030 Notes | Senior indebtedness    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations 1,007.7 1,009.0
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 97.8 62.6
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 1,378.3 1,243.8
Fair Value | 2026 Senior Convertible Debt | Senior subordinated convertible debt    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value disclosure for debt obligations $ 1,036.3 $ 875.0