Related Party Transactions - Receivables from and Payables to Related Broker-Dealers (Details) - Related Party - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Transactions with Freedom
Related Party Transaction [Line Items]
Receivables from related parties	$ 1,900,000	$ 1,400,000
Open Derivative Contracts with Cantor
Related Party Transaction [Line Items]
Receivables from related parties	4,400,000	3,100,000
Payables to related parties	3,000,000	5,800,000
Fails and Pending Trades with Cantor
Related Party Transaction [Line Items]
Receivables from related parties		0
Payables to related parties	$ 5,700,000	$ 0

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 310
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-Topic 954
-SubTopic 310
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481058/954-310-45-1

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