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Segment Analysis - Reportable Segments (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Sep. 30, 2023
Segment Reporting Information [Line Items] |  |  |
Total revenues | $ 19,573.0 | $ 13,011.6 |
Operating revenues | 784.2 | 654.8 |
Net operating revenues (loss) | 421.6 | 382.0 |
Net contribution | 336.8 | 291.6 |
Segment income | 216.1 | 172.9 |
Net operating revenues (loss) within Corporate | (15.6) | (11.1) |
Overhead costs and expenses | (104.8) | (89.7) |
Gain on acquisition | 0.0 | 23.5 |
Income before tax | 95.7 | 95.6 |
Assets | 23,244.8 |  | $ 21,938.7
Corporate |  |  |
Segment Reporting Information [Line Items] |  |  |
Total revenues | 9.2 | 12.8 |
Operating revenues | 9.2 | 12.8 |
Net operating revenues (loss) | (15.6) | (11.1) |
Assets | 839.0 |  | 812.3
Eliminations |  |  |
Segment Reporting Information [Line Items] |  |  |
Total revenues | (12.2) | (9.8) |
Operating revenues | (12.2) | (9.8) |
Commercial |  |  |
Segment Reporting Information [Line Items] |  |  |
Net contribution | 126.4 | 115.7 |
Segment income | 87.2 | 82.8 |
Commercial | Operating Segments |  |  |
Segment Reporting Information [Line Items] |  |  |
Total revenues | 18,978.0 | 12,293.5 |
Operating revenues | 198.4 | 182.4 |
Net operating revenues (loss) | 163.4 | 152.7 |
Assets | 4,712.7 |  | 4,676.3
Institutional |  |  |
Segment Reporting Information [Line Items] |  |  |
Net contribution | 100.2 | 94.6 |
Segment income | 65.2 | 62.0 |
Institutional | Operating Segments |  |  |
Segment Reporting Information [Line Items] |  |  |
Total revenues | 435.7 | 343.5 |
Operating revenues | 435.7 | 343.5 |
Net operating revenues (loss) | 148.6 | 143.2 |
Assets | 16,140.9 |  | 15,059.3
Retail |  |  |
Segment Reporting Information [Line Items] |  |  |
Net contribution | 62.6 | 39.2 |
Segment income | 28.7 | (4.2) |
Retail | Operating Segments |  |  |
Segment Reporting Information [Line Items] |  |  |
Total revenues | 101.7 | 316.2 |
Operating revenues | 92.5 | 70.5 |
Net operating revenues (loss) | 67.0 | 43.9 |
Assets | 1,138.2 |  | 1,014.2
Payments |  |  |
Segment Reporting Information [Line Items] |  |  |
Net contribution | 47.6 | 42.1 |
Segment income | 35.0 | 32.3 |
Payments | Operating Segments |  |  |
Segment Reporting Information [Line Items] |  |  |
Total revenues | 60.6 | 55.4 |
Operating revenues | 60.6 | 55.4 |
Net operating revenues (loss) | 58.2 | $ 53.3 |
Assets | $ 414.0 |  | $ 376.6

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