Note 4 - Mortgage Loans, Net (Details Textual) - Mortgage Receivable [Member] $ in Thousands	6 Months Ended
Jun. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Mortgage Loans on Real Estate, Number of Loans 1	6	4
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Ending Balance	$ 22,900	$ 19,700
Allowance for Loan and Lease Losses, Real Estate	$ 12,700	$ 12,700
Mortgage Loans on Real Estate, Number of Loans Originated During Period	2
Construction Loans [Member]
Loans and Leases Receivable, Gross, Total	$ 13,100
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	8.50%
Mortgage Loans on Real Estate, New Mortgage Loans, Extension Term	180 days
Mortgage Loan [Member]
Loans and Leases Receivable, Gross, Total	$ 3,000
Mortgage Loans On RealEstate, Basis Spread on Variable Rate	6.00%
Mortgage Loans on Real Estate, Exit Fee	1.00%
Mortgage Loan [Member] \| Minimum [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	8.00%
Performing Financial Instruments [Member]
Mortgage Loans on Real Estate, Number of Loans 1	4	2
Mortgage Loans, Weighted Average Interest Rate	9.71%	9.69%
Nonperforming Financial Instruments [Member]
Mortgage Loans on Real Estate, Number of Loans 1	2	2
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Ending Balance	$ 0	$ 0

The percentage of exit fee on mortgage loan.

No definition available.

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Namespace Prefix:	ifcn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The period in which the loan may be extended.

+ References

No definition available.

+ Details

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Namespace Prefix:	ifcn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of mortgage loans in real estate at the end of the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	ifcn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of mortgage loans within investment in mortgage loan on real estate originated during the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	ifcn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on mortgage loans on real estate.

+ References

No definition available.

+ Details

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Namespace Prefix:	ifcn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate on mortgage loans.

+ References

No definition available.

+ Details

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Namespace Prefix:	ifcn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Interest rate of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Paragraph Column B
-Subsection 29

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Column B))
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

+ Details

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Namespace Prefix:	srt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82921503&loc=d3e21338-158488

+ Details

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

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Column G))
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	debit
Period Type:	instant

- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
Data Type:	na
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- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
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- Details

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