Regulatory Capital Requirements - Additional Information (Detail)	Mar. 31, 2023 USD ($)
Brokers And Dealers [Line Items]
Securities reserve deposit	$ 51,500,000
U.S. Subsidiaries
Brokers And Dealers [Line Items]
Aggregate net capital and financial resources in excess of required level	541,000.0
Aggregate net capital and financial resources, minimum capital requirement	29,000.0
U.S. Broker-Dealer Subsidiaries
Brokers And Dealers [Line Items]
Aggregate net capital and financial resources in excess of required level	325,500,000
Aggregate net capital and financial resources, minimum capital requirement	$ 4,200,000

Brokers and dealers.

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Amount of net capital in excess of minimum required net capital, calculated under Alternative Standard.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

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Minimum amount of net capital of broker-dealer and its subsidiary, calculated under Alternative Standard.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

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Securities deposited in a special reserve account for the exclusive benefit of customers pursuant to SEC Regulations.

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