Subsequent Events - Additional Information (Details)	12 Months Ended
Dec. 31, 2021	Mar. 11, 2022
Subsequent Event [Line Items]
Subsequent Event Description	The manager evaluated events occurring subsequent to December 31, 2021 and determined that there were no other events or transactions occurring during this reporting period that require recognition or disclosure in the financial statements.
Line of credit facility, interest rate	5.00%
Total Outstanding Membership Interest, Percentage		53.00%
Maximum Percentage of Weighted Average Number of Members Outstanding Units During Twelve Months for Redemption	5.00%
Revolving Credit Facility [Member]
Subsequent Event [Line Items]
Line of credit facility, interest rate	5.00%
Revolving Credit Facility [Member] \| Ameribor
Subsequent Event [Line Items]
Line of credit facility, interest rate	3.25%

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

No definition available.

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Namespace Prefix:	ck0001448038_
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Balance Type:	na
Period Type:	duration

- Definition

Total Outstanding Membership Interest, Percentage

+ References

No definition available.

+ Details

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

- Definition

The effective interest rate at the end of the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Describes the event or transaction that occurred between the balance sheet date and the date the financial statements are issued or available to be issued.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

+ Details

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Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type: