Summary of Significant Accounting Policies (Summary of Revenue Concentration) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Summary of Significant Accounting Policies [Abstract]
CDO asset management revenue and related service	$ 8,678	$ 10,999	$ 13,664
Total asset management revenue	9,682	14,496	19,239
Revenues	$ 46,156	$ 55,750	$ 57,517
CDO asset management % as compared to total asset management fees	90.00%	76.00%	71.00%
CDO asset management % as compared to total revenues	19.00%	20.00%	24.00%
Principal transactions and other income	$ 78	$ 7,979	$ (6,668)
Principal transactions % as compared to total revenues	0.00%	14.00%	(12.00%)

Collateralized Debt Obligation Asset Management Percentage Compare to Total Asset Management Fees

No definition available.

Name:	ifmi_CollateralizedDebtObligationAssetManagementPercentageCompareToTotalAssetManagementFees
Namespace Prefix:	ifmi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Collateralized Debt Obligation Asset Management Percentage Compare to Total Revenues

+ References

No definition available.

+ Details

Name:	ifmi_CollateralizedDebtObligationAssetManagementPercentageCompareToTotalRevenues
Namespace Prefix:	ifmi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Collateralized Debt Obligation Asset Management Revenue and Related Service Agreements

+ References

No definition available.

+ Details

Name:	ifmi_CollateralizedDebtObligationAssetManagementRevenueAndRelatedServiceAgreements
Namespace Prefix:	ifmi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Principal transactions include all gains, losses, and income (interest and dividend) from securities or loans classified as other investments, at fair value (including gains and losses on derivatives classified as other investments, at fair value) in the consolidated balance sheets. Other income includes foreign currency gains and losses, interest earned on cash and cash equivalents, and other miscellaneous income.

+ References

No definition available.

+ Details

Name:	ifmi_PrincipalTransactionsAndOtherIncome
Namespace Prefix:	ifmi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Principal Transactions as a Percentage of Total Revenues

+ References

No definition available.

+ Details

Name:	ifmi_PrincipalTransactionsAsPercentageOfTotalRevenues
Namespace Prefix:	ifmi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Amount of fixed fee revenue for the management of an investment fund portfolio. Excludes investment advisory, distribution and servicing, and performance fees.

+ References

No definition available.

+ Details

Name:	us-gaap_AssetManagementFees1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

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