Stockholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Apr. 30, 2026 |
Apr. 30, 2025 |
Apr. 30, 2026 |
Apr. 30, 2025 |
Sep. 30, 2025 |
|
| Stockholders' Equity Note [Abstract] | |||||
| Share repurchase program, authorized amount for repurchase | $ 2,000.0 | ||||
| Share repurchase program, remaining authorized amount for repurchase | $ 860.8 | $ 860.8 | |||
| Stock repurchase (in shares) | 0.2 | 0.5 | 1.3 | 0.5 | |
| Treasury stock repurchase | $ 13.1 | $ 40.6 | $ 105.6 | $ 40.6 | |
| Stock repurchase at an average price (in dollars per share) | $ 75.84 | $ 75.60 | $ 81.21 | $ 75.60 | |