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Regulatory Capital Requirements - Additional Information (Detail) $ in Millions | Sep. 30, 2025 USD ($)
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U.S. Subsidiaries |
Brokers And Dealers [Line Items] |
Aggregate net capital and financial resources in excess of required level | $ 603.4
Aggregate net capital and financial resources, minimum capital requirement | 43.3
U.S. Broker-Dealer Subsidiaries |
Brokers And Dealers [Line Items] |
Aggregate net capital and financial resources in excess of required level | 3.8
Aggregate net capital and financial resources, minimum capital requirement | 327.8
Securities reserve deposit | $ 48.4

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- Definition Amount of net capital in excess of minimum required net capital, calculated under Alternative Standard. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name Rule 15c3-1 -Number 240 -Section 15c3-1 -Publisher SEC + Details
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- Definition Minimum amount of net capital of broker-dealer and its subsidiary, calculated under Alternative Standard. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name Rule 15c3-1 -Number 240 -Section 15c3-1 -Publisher SEC + Details
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