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v3.22.2.2

Description of Business and Significant Accounting Policies (Details) |  | 12 Months Ended
--- | --- | ---
Oct. 01, 2020 USD ($) | Sep. 30, 2022 USD ($) client country $ / shares shares | Sep. 30, 2021 USD ($) $ / shares shares | Sep. 30, 2020 USD ($) | Sep. 30, 2019 | Sep. 30, 2018
Number of countries in which entity operates (more than) | country |  | 180 |  |  |  |
Number of commercial, institutional and global payment clients (more than) | client |  | 54,000 |  |  |  |
Number retail clients (more than) | client |  | 400,000 |  |  |  |
Translation gains |  |  | $ 800,000 | $ 0 |  |
Net liabilities denominated in argentine pesos |  | $ 400,000 |  |  |  |
Net assets denominated in argentine pesos |  |  | 400,000 |  |  |
Cash denominated in argentine pesos (less than) |  | 100,000 | 100,000 |  |  |
Net nonmonetary denominated in Argentine pesos |  | 1,100,000 | 900,000 |  |  |
Cash held at banks and money market funds - segregated |  | 2,461,600,000 | 2,260,300,000 |  |  |
US government obligations and other securities |  | 786,000,000 | 200,000 |  |  |
Commodities warehouse receipts |  | 19,700,000 | 13,900,000 |  |  |
Cash and cash equivalents - deposits and receivables |  | 2,515,000,000 | 3,139,600,000 |  |  |
US government securities and other securities - deposits and receivables |  | $ 4,272,900,000 | 810,700,000 |  |  |
Acquired finite-lived intangible asset, weighted average useful life |  | 1 year |  |  |  |
Goodwill impairment charges |  | $ 0 | 0 | $ 0 |  |
Fair Value of exchange memberships |  | $ 6,200,000 | $ 6,800,000 |  |  |
Preferred stock - authorized (in shares) | shares |  | 1,000,000 | 1,000,000 |  |  |
Preferred stock - par value (in dollar per share) | $ / shares |  | $ 0.01 | $ 0.01 |  |  |
Preferred stock - outstanding (in shares) | shares |  | 0 | 0 |  |  |
Accounting Standards Update [Extensible Enumeration] |  |  |  | Accounting Standards Update 2016-13 [Member] | Accounting Standards Update 2018-02 [Member] | Accounting Standards Update 2018-02 [Member]
Retained earnings |  | $ 889,600,000 | $ 682,500,000 |  |  |
Income tax expense |  | 70,100,000 | 37,800,000 | $ 37,100,000 |  |
Cumulative transition adjustment |  |  |  |  |  |
Retained earnings | $ (6,200,000) |  |  |  |  |
Income tax expense | $ 2,000,000 |  |  |  |  |
Exchange Memberships Representing an Ownership Interest |  |  |  |  |  |
Memberships in exchanges owned |  | 5,500,000 | 5,500,000 |  |  |
Exchange Memberships not Representing an Ownership Interest |  |  |  |  |  |
Memberships in exchanges owned |  | $ 5,800,000 | $ 6,000,000 |  |  |
Minimum |  |  |  |  |  |
Property plant and equipment, useful life |  | 3 years |  |  |  |
Identifiable intangible assets |  | 5 years |  |  |  |
Maximum |  |  |  |  |  |
Property plant and equipment, useful life |  | 10 years |  |  |  |
Identifiable intangible assets |  | 20 years |  |  |  |
Capitalized software development |  |  |  |  |  |
Property plant and equipment, useful life |  | 3 years |  |  |  |
Argentina |  |  |  |  |  |
Translation gains |  | $ 2,100,000 |  |  |  |
Argentina | Revenue Benchmark | Geographic Concentration Risk |  |  |  |  |  |
Percentage of operating revenues |  | 1.00% |  |  |  |
Retail |  |  |  |  |  |
Number of countries in which entity operates (more than) | country |  | 180 |  |  |  |

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