Summary of Significant Accounting Policies - Additional Information (Detail) £ in Millions, $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
|
Mar. 31, 2026
USD ($)
|
Mar. 31, 2025
USD ($)
|
Mar. 31, 2024
USD ($)
|
Mar. 31, 2026
GBP (£)
|
|
| Accounting Policies [Line Items] | ||||
| Foreign currency transaction gain (loss), before tax | $ (59.6) | $ 42.6 | $ 49.2 | |
| Capitalized software development costs | 0.0 | 0.0 | 2.6 | |
| Product engineering costs | 226.8 | 164.6 | 145.6 | |
| Advertising expense | $ 100.5 | 62.5 | $ 40.6 | |
| The maximum term of share awards granted | 10 years | |||
| Cash and cash equivalents | $ 27,802.2 | 18,066.3 | ||
| Customer funds included in cash and cash equivalents | 14,824.1 | 7,503.0 | ||
| Customer funds safeguarded by comparable guarantees | 1,119.1 | £ 845.0 | ||
| Money Market Funds [Member] | ||||
| Accounting Policies [Line Items] | ||||
| Cash and cash equivalents | 7,592.1 | 7,034.4 | ||
| Government Treasury Bonds and Highly-Rated Corporate Paper [Member] | ||||
| Accounting Policies [Line Items] | ||||
| Cash and cash equivalents | $ 4,582.7 | $ 6,013.6 | ||