Limited liability company percentage of profit to be allocated to manager.

No definition available.

Name:	ck0001448038_LimitedLiabilityCompanyPercentageOfProfitToBeAllocatedToManager
Namespace Prefix:	ck0001448038_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Limited liability company percentage of profit to be allocated to members.

+ References

No definition available.

+ Details

Name:	ck0001448038_LimitedLiabilityCompanyPercentageOfProfitToBeAllocatedToMembers
Namespace Prefix:	ck0001448038_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Limited partners capital account units issued value.

+ References

No definition available.

+ Details

Name:	ck0001448038_LimitedPartnersCapitalAccountUnitsIssuedValue
Namespace Prefix:	ck0001448038_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The percentage of company net income or loss allocated to the company's managers before any allocation to the limited members.

+ References

No definition available.

+ Details

Name:	ck0001448038_ManagersShareOfNetIncomeLoss
Namespace Prefix:	ck0001448038_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum capital units for redemption per quarter per individual.

+ References

No definition available.

+ Details

Name:	ck0001448038_MaximumCapitalUnitsForRedemptionPerQuarterPerIndividual
Namespace Prefix:	ck0001448038_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of members outstanding units for redemption per quarter per individual.

+ References

No definition available.

+ Details

Name:	ck0001448038_MaximumPercentageOfMembersOutstandingUnitsForRedemptionPerQuarterPerIndividual
Namespace Prefix:	ck0001448038_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of weighted average number of members outstanding units during twelve months.

+ References

No definition available.

+ Details

Name:	ck0001448038_MaximumPercentageOfWeightedAverageNumberOfMembersOutstandingUnitsDuringTwelveMonthsForRedemption
Namespace Prefix:	ck0001448038_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Organization and general details.

+ References

No definition available.

+ Details

Name:	ck0001448038_OrganizationAndGeneralDetailsLineItems
Namespace Prefix:	ck0001448038_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Redemption value percentage of purchase price or capital account balance.

+ References

No definition available.

+ Details

Name:	ck0001448038_RedemptionValuePercentageOfPurchasePriceOrCapitalAccountBalance
Namespace Prefix:	ck0001448038_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Total Outstanding Membership Interest, Percentage

+ References

No definition available.

+ Details

Name:	ck0001448038_TotalOutstandingMembershipInterestPercentage
Namespace Prefix:	ck0001448038_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted Average Number of Units Outstanding, Percentage

+ References

No definition available.

+ Details

Name:	ck0001448038_WeightedAverageNumberOfUnitsOutstandingPercentage
Namespace Prefix:	ck0001448038_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Distribution/dividend policy defined in the operating or partnership agreement of the LLC or LP, which governs the distributions of cash or stock or units to members or limited partners. Policy may include minimum amount of cash or stock or units, allocation method among unit holders, timing of payment, and reinvestment procedures.

+ References

No definition available.

+ Details

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

- Definition

Percentage investment held by the managing member or general partner of the limited liability company (LLC) or limited partnership (LP).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

+ Details

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

- Definition

The number of limited partner units issued.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187171-122770

+ Details

Name:	us-gaap_LimitedPartnersCapitalAccountUnitsIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from the issuance of common limited partners units during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

+ Details

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

- Details

Name:	srt_StatementScenarioAxis=ck0001448038_RedemptionBetweenOneToTwoYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=ck0001448038_RedemptionBetweenTwoToThreeYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=ck0001448038_RedemptionBetweenThreeToFourYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=ck0001448038_RedemptionBetweenFourToFiveYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=ck0001448038_RedemptionAfterFiveYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PartnerCapitalComponentsAxis=ck0001448038_DistributionReinvestmentPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_MemberUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=ck0001448038_RedwoodMortgageCorpMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Organization and General - Additional Information (Details)	3 Months Ended	117 Months Ended
	Mar. 31, 2022 USD ($) Unit	May 31, 2019	Mar. 11, 2022	May 09, 2019 USD ($) shares
Organization and General (Details) [Line Items]
Members or partners capital, description	Cash available for distribution at the end of each calendar month is allocated ninety-nine percent (99%) to the members and one percent (1%) to the manager.
Percentage of distribution allocated to members	99.00%
Maximum capital units for redemption per quarter per individual \| Unit	100,000
Maximum percentage of members total outstanding units for redemption per quarter per individual	25.00%
Weighted Average Number of Units Outstanding, Percentage	(5.00%)
Maximum percentage of weighted average number of members outstanding units during twelve months for redemption	5.00%
Total Outstanding Membership Interest, Percentage			53.00%
Redemption Between One To Two Years [Member]
Organization and General (Details) [Line Items]
Redemption value percentage of purchase price or capital account balance	92.00%
Redemption Between Two to Three Years [Member]
Organization and General (Details) [Line Items]
Redemption value percentage of purchase price or capital account balance	94.00%
Redemption Between Three to Four Years [Member]
Organization and General (Details) [Line Items]
Redemption value percentage of purchase price or capital account balance	96.00%
Redemption Between Four to Five Years [Member]
Organization and General (Details) [Line Items]
Redemption value percentage of purchase price or capital account balance	98.00%
Redemption After Five Years [Member]
Organization and General (Details) [Line Items]
Redemption value percentage of purchase price or capital account balance	100.00%
DRIP [Member]
Organization and General (Details) [Line Items]
Gross proceeds from unit sales	$ 6,660,000
Member Units [Member]
Organization and General (Details) [Line Items]
Capital unit sold in public offering, shares \| shares				15,000,000
Capital unit sold in public offering, value				$ 15,000,000
RMC [Member]
Organization and General (Details) [Line Items]
Ownership interest held by the manager		1.00%
Managers share of net income or loss		1.00%
Percentage of profits and losses allocated to manager	1.00%