Receivable from and Payable to Customers (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Receivables and Payable to Customers [Abstract]
Receivable from customers	$ 224,455	$ 103,963
Payable to customers	$ 2,732,428	$ 1,680,326

Amount due from customers for fees and charges arising from transactions related to the entity's brokerage activities and operations.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 940
-SubTopic 310
-URI http://asc.fasb.org/subtopic&trid=2176284

Name:	us-gaap_ReceivablesFromCustomers
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant