Segment and Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Financial information for the Company's segments
Net trading	$ 19,951	$ 16,240	$ 37,642	$ 43,514
Asset management	4,608	5,255	9,545	11,225
New issue and advisory	189	1,131	1,266	1,240
Principal transactions and other income	289	831	(4,656)	(208)
Total revenues	25,037	23,457	43,797	55,771
Total operating expenses	24,207	31,635	48,170	62,362
Operating income / (loss)	830	(8,178)	(4,373)	(6,591)
Income / (loss) from equity method affiliates	1,526	4,435	2,042	4,530
Other non operating income / (expense)	(5,461)	(1,447)	(6,673)	(2,929)
Income / (loss) before income taxes	(3,105)	(5,190)	(9,004)	(4,990)
Income tax expense / (benefit)	63	(133)	54	(346)
Net income / (loss)	(3,168)	(5,057)	(9,058)	(4,644)
Less: Net income / (loss) attributable to the non-controlling interest	1,090	1,686	3,121	1,648
Net income / (loss) attributable to IFMI	(2,078)	(3,371)	(5,937)	(2,996)
Other statement of operations data:
Depreciation and amortization (included in total operating expense)	343	503	734	973
Balance sheet data:
Total assets	503,035	455,733	503,035	455,733	420,590
Investment in equity method affiliates (included in total assets)	2,390	1,488	2,390	1,488
Goodwill	11,113	11,176	11,113	11,176	11,206
Intangible assets (included in other assets)	538	538	538	538
Capital Markets [Member]
Financial information for the Company's segments
Net trading	19,951	16,240	37,642	43,514
New issue and advisory	189	1,131	1,266	1,240
Principal transactions and other income	(7)	156	(34)	174
Total revenues	20,133	17,527	38,874	44,928
Total operating expenses	18,806	18,733	37,676	38,187
Operating income / (loss)	1,327	(1,206)	1,198	6,741
Other non operating income / (expense)	(4,289)	13	(4,224)	13
Income / (loss) before income taxes	(2,962)	(1,193)	(3,026)	6,754
Net income / (loss)	(2,962)	(1,193)	(3,026)	(53)
Less: Net income / (loss) attributable to the non-controlling interest	109	53	238
Net income / (loss) attributable to IFMI	(2,853)	(1,140)	(2,788)	6,807
Other statement of operations data:
Depreciation and amortization (included in total operating expense)	223	116	452	145
Balance sheet data:
Total assets	444,297	370,731	444,297	370,731
Goodwill	7,937	8,000	7,937	8,000
Intangible assets (included in other assets)	538	538	538	538
Asset Management [Member]
Financial information for the Company's segments
Asset management	4,608	5,255	9,545	11,225
Principal transactions and other income	233	342	393	920
Total revenues	4,841	5,597	9,938	12,145
Total operating expenses	1,762	1,040	2,842	3,317
Operating income / (loss)	3,079	4,557	7,096	8,828
Income / (loss) from equity method affiliates		4,359		4,359
Income / (loss) before income taxes	3,079	8,916	7,096	13,187
Net income / (loss)	3,079	8,916	7,096	13,187
Net income / (loss) attributable to IFMI	3,079	8,916	7,096	13,187
Other statement of operations data:
Depreciation and amortization (included in total operating expense)	3	3	7	7
Balance sheet data:
Total assets	7,219	21,553	7,219	21,553
Goodwill	3,176	3,176	3,176	3,176
Intangible assets (included in other assets)
Principal Investing [Member]
Financial information for the Company's segments
Principal transactions and other income	63	333	(5,015)	(1,302)
Total revenues	63	333	(5,015)	(1,302)
Total operating expenses	75	102	156	157
Operating income / (loss)	(12)	231	(5,171)	(1,459)
Income / (loss) from equity method affiliates	1,526	76	2,042	171
Income / (loss) before income taxes	1,514	307	(3,129)	(1,288)
Net income / (loss)	1,514	307	(3,129)	(1,288)
Net income / (loss) attributable to IFMI	1,514	307	(3,129)	(1,288)
Balance sheet data:
Total assets	39,995	44,020	39,995	44,020
Investment in equity method affiliates (included in total assets)	2,390	1,488	2,390	1,488
Goodwill
Intangible assets (included in other assets)
Segment Total [Member]
Financial information for the Company's segments
Net trading	19,951	16,240	37,642	43,514
Asset management	4,608	5,255	9,545	11,225
New issue and advisory	189	1,131	1,266	1,240
Principal transactions and other income	289	831	(4,656)	(208)
Total revenues	25,037	23,457	43,797	55,771
Total operating expenses	20,643	19,875	40,674	41,661
Operating income / (loss)	4,394	3,582	3,123	14,110
Income / (loss) from equity method affiliates	1,526	4,435	2,042	4,530
Other non operating income / (expense)	(4,289)	13	(4,224)	13
Income / (loss) before income taxes	1,631	8,030	941	18,653
Net income / (loss)	1,631	8,030	941	18,653
Less: Net income / (loss) attributable to the non-controlling interest	109	53	238	53
Net income / (loss) attributable to IFMI	1,740	8,083	1,179	18,706
Other statement of operations data:
Depreciation and amortization (included in total operating expense)	226	119	459	152
Balance sheet data:
Total assets	491,511	436,304	491,511	436,304
Investment in equity method affiliates (included in total assets)	2,390	1,488	2,390	1,488
Goodwill	11,113	11,176	11,113	11,176
Intangible assets (included in other assets)	538	538	538	538
Unallocated [Member]
Financial information for the Company's segments
Total operating expenses	3,564	11,760	7,496	20,701
Operating income / (loss)	(3,564)	(11,760)	(7,496)	(20,701)
Other non operating income / (expense)	(1,172)	(1,460)	(2,449)	(2,942)
Income / (loss) before income taxes	(4,736)	(13,220)	(9,945)	(23,643)
Income tax expense / (benefit)	63	(133)	54	(346)
Net income / (loss)	(4,799)	(13,087)	(9,999)	(23,297)
Less: Net income / (loss) attributable to the non-controlling interest	981	1,633	2,883	1,595
Net income / (loss) attributable to IFMI	(3,818)	(11,454)	(7,116)	(21,702)
Other statement of operations data:
Depreciation and amortization (included in total operating expense)	117	384	275	821
Balance sheet data:
Total assets	11,524	19,429	11,524	19,429
Goodwill
Intangible assets (included in other assets)