v3.26.1
Segment Reporting - Summary of Net Revenue by Geographic Areas (Detail) - USD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Revenue From External Customers By Geographic Areas [Line Items]      
Transaction revenue $ 1,893.6 $ 1,546.3 $ 1,323.1
Interest income on customer balances 806.1 758.3 610.0
Interest expense on customer liabilities (196.9) (205.7) (157.0)
Net revenue 2,502.8 2,098.9 1,776.1
Europe (excluding UK) [Member]      
Revenue From External Customers By Geographic Areas [Line Items]      
Transaction revenue 569.4 467.0 404.6
Interest income on customer balances 271.1 281.1 231.8
Interest expense on customer liabilities (127.3) (154.8) (135.6)
Net revenue 713.2 593.3 500.8
Asia-Pacific [Member]      
Revenue From External Customers By Geographic Areas [Line Items]      
Transaction revenue 450.5 336.5 272.0
Interest income on customer balances 65.4 47.0 25.5
Interest expense on customer liabilities 0.0 0.0 0.0
Net revenue 515.9 383.5 297.5
United States of America [Member]      
Revenue From External Customers By Geographic Areas [Line Items]      
Transaction revenue 261.9 229.7 209.6
Interest income on customer balances 160.1 136.9 101.9
Interest expense on customer liabilities (56.8) (49.1) (21.4)
Net revenue 365.2 317.5 290.1
United Kingdom [Member]      
Revenue From External Customers By Geographic Areas [Line Items]      
Transaction revenue 329.1 288.9 254.8
Interest income on customer balances 257.2 258.8 223.9
Interest expense on customer liabilities 0.0 0.0 0.0
Net revenue 586.3 547.7 478.7
Rest of the World [Member]      
Revenue From External Customers By Geographic Areas [Line Items]      
Transaction revenue 282.7 224.2 182.1
Interest income on customer balances 52.3 34.5 26.9
Interest expense on customer liabilities (12.8) (1.8) 0.0
Net revenue $ 322.2 $ 256.9 $ 209.0