Commitments and Contingencies (Details) [Line Items]

No definition available.

Name:	rily_CommitmentsAndContingenciesDetailsLineItems
Namespace Prefix:	rily_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Credit Agreement, Quarterly Payable, Cash Percentage

+ References

No definition available.

+ Details

Name:	rily_CreditAgreementQuarterlyPayableCashPercentage
Namespace Prefix:	rily_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Credit Agreement, Quarterly Payable, Penny Warrant Percentage

+ References

No definition available.

+ Details

Name:	rily_CreditAgreementQuarterlyPayablePennyWarrantPercentage
Namespace Prefix:	rily_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Guarantor Obligations, Annual Fee Receivable

+ References

No definition available.

+ Details

Name:	rily_GuarantorObligationsAnnualFeeReceivable
Namespace Prefix:	rily_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount related to Indemnity amount.

+ References

No definition available.

+ Details

Name:	rily_IndemnityAmount
Namespace Prefix:	rily_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Indemnity Amounts Remained Outstanding

+ References

No definition available.

+ Details

Name:	rily_IndemnityAmountsRemainedOutstanding
Namespace Prefix:	rily_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number Of Written Put Agreements

+ References

No definition available.

+ Details

Name:	rily_NumberOfWrittenPutAgreements
Namespace Prefix:	rily_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Payments For Other Commitment

+ References

No definition available.

+ Details

Name:	rily_PaymentsForOtherCommitment
Namespace Prefix:	rily_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Sale Of Stock, Conversion Limitation, Percent

+ References

No definition available.

+ Details

Name:	rily_SaleOfStockConversionLimitationPercent
Namespace Prefix:	rily_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-4

+ Details

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitment.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermPurchaseCommitmentAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-1

Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-10

+ Details

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-4

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-9

+ Details

Name:	us-gaap_LossContingencyDamagesSoughtValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3

+ Details

Name:	us-gaap_OtherCommitment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Value of the difference between preference in liquidation and the par or stated values of the preferred shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-4

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(d))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

+ Details

Name:	us-gaap_PreferredStockLiquidationPreferenceValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_PaymentGuaranteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=rily_SorrentoTherapeuticsInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=rily_BabcockAndWilcoxMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=us-gaap_GuaranteesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

COMMITMENTS AND CONTINGENCIES (Details) € in Thousands, $ in Thousands					3 Months Ended	12 Months Ended
	Jul. 11, 2025 USD ($)	Jan. 18, 2024 USD ($)	Dec. 22, 2021 EUR (€)	Aug. 10, 2020 USD ($)	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2025 EUR (€)	Jan. 31, 2026 USD ($)	Nov. 14, 2025 USD ($)	Sep. 30, 2025 USD ($)	Jun. 30, 2025 agreement	Apr. 30, 2025 USD ($) agreement	Dec. 31, 2024 USD ($)	Sep. 21, 2023 USD ($)	Jun. 30, 2021 USD ($)
Commitments and Contingencies (Details) [Line Items]
Loss contingency, damages sought, value	$ 37,500
Credit facility success fees, percentage		2.00%
Credit agreement, quarterly payable, cash percentage		50.00%
Credit agreement, quarterly payable, penny warrant percentage		50.00%
Number of written put agreements \| agreement											2	2
Other commitment						$ 925,000			$ 12,700	$ 1,000,000		$ 15,000
Long-term purchase commitment, amount						500
Payments for other commitment						$ 75,000			$ 2,300
Sale of stock, conversion limitation (in percent)						19.99%
Preferred stock, liquidation preference						$ 122,142							$ 114,082
Subsequent Event
Commitments and Contingencies (Details) [Line Items]
Preferred stock, liquidation preference								$ 150,000
Payment Guarantee
Commitments and Contingencies (Details) [Line Items]
Aggregate principal amounts (in dollars)		$ 150,000
Sorrento Therapeutics, Inc.
Commitments and Contingencies (Details) [Line Items]
Loss contingency accrual														$ 32,166
Babcock and Wilcox
Commitments and Contingencies (Details) [Line Items]
Indemnity amount			€ 30,000	$ 29,970		$ 2,997	€ 5,000
Indemnity amounts remained outstanding					$ 0
Babcock and Wilcox \| Guarantees
Commitments and Contingencies (Details) [Line Items]
Contractual obligation															$ 935
Babcock and Wilcox \| Maximum \| Guarantees
Commitments and Contingencies (Details) [Line Items]
Aggregate principal amounts (in dollars)															$ 110,000