Due from StockCross.

No definition available.

Name:	SIEB_DueFromStockcross
Namespace Prefix:	SIEB_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Payable to StockCross

+ References

No definition available.

+ Details

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- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

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- Definition

Amount of income (loss) for proportionate share of equity method investee's income (loss).

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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Related Party Disclosures (Details) - USD ($)	3 Months Ended		9 Months Ended
Related Party Disclosures (Details) - USD ($)	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jan. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Due from Stockcross to MSCO	$ 693,000		$ 693,000			$ 310,000
Percentage of purchase outstanding shares of StockCross					15.00%
Earnings of equity method investment	30,000		84,000
MSCO [Member]
Related Party Transaction [Line Items]
Due from Stockcross to MSCO	1,700,000		1,700,000			1,300,000
Payable to StockCross	27,000		27,000			$ 46,000
PWC [Member]
Related Party Transaction [Line Items]
Related party revenues	$ 3,000	$ 16,000	$ 67,000	$ 61,000