XML 77 R66.htm IDEA: XBRL DOCUMENT v3.25.1

Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Financial Instruments with Off-Balance Sheet Risk [Abstract]
Margin loans extended	$ 390.1		$ 403.8
Receivables from customers	79.6		$ 84.4
Unsettled customer transactions

X

- Definition

Margin loans extended.

+ References

No definition available.

+ Details

Name:	sieb_MarginLoansExtended
Namespace Prefix:	sieb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

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

+ References

No definition available.

+ Details

Name:	sieb_ReceivablesFromCustomers1
Namespace Prefix:	sieb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Unsettled customer transactions.

+ References

No definition available.

+ Details

Name:	sieb_UnsettledCustomerTransactions
Namespace Prefix:	sieb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration