Condensed Consolidated Income Statements Statement (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenues:
Sales of physical commodities	$ 17,201.0	$ 20,464.7	$ 51,238.5	$ 51,179.9
Trading gains	94.8	70.0	206.2	117.9
Commission and clearing fees	45.4	31.1	118.9	105.6
Consulting and management fees	7.1	5.2	20.6	15.2
Interest income	2.7	2.3	7.7	7.8
Other income	0.1	0.1	0.6	0.8
Total revenues	17,351.1	20,573.4	51,592.5	51,427.2
Cost of sales of physical commodities	17,227.3	20,468.0	51,252.8	51,112.1
Operating revenues	123.8	105.4	339.7	315.1
Interest expense	2.6	2.0	8.3	9.1
Net revenues	121.2	103.4	331.4	306.0
Non-interest expenses:
Compensation and benefits	54.6	44.0	155.5	129.6
Clearing and related expenses	30.6	18.0	80.4	58.4
Introducing broker commissions	7.9	6.3	21.7	17.7
Communication and data services	6.3	4.2	16.5	11.1
Occupancy and equipment rental	2.7	2.1	8.2	6.1
Professional fees	3.3	2.9	9.6	6.9
Depreciation and amortization	1.9	1.3	5.3	3.4
Bad debts and impairments	0.6	1.2	0.6	5.7
Other	7.4	6.1	24.8	20.6
Total non-interest expenses	115.3	86.1	322.6	259.5
Income from continuing operations, before tax	5.9	17.3	8.8	46.5
Income tax expense	1.2	7.0	2.2	17.1
Net income from continuing operations	4.7	10.3	6.6	29.4
Income from discontinued operations, net of tax	0	0	0	0.2
Net income	4.7	10.3	6.6	29.6
Add: Net loss attributable to noncontrolling interests	0	0.1	0.1	0.2
Net income attributable to INTL FCStone Inc. common stockholders	4.7	10.4	6.7	29.8
Basic earnings per share:
Income from continuing operations attributable to INTL FCStone Inc. common stockholders	$ 0.24	$ 0.58	$ 0.35	$ 1.67
Income from discontinued operations attributable to INTL FCStone Inc. common stockholders	$ 0.00	$ 0.00	$ 0.00	$ 0.01
Net income attributable to INTL FCStone Inc. common stockholders	$ 0.24	$ 0.58	$ 0.35	$ 1.68
Diluted earnings per share:
Income from continuing operations attributable to INTL FCStone Inc. common stockholders	$ 0.23	$ 0.55	$ 0.33	$ 1.56
Income from discontinued operations attributable to INTL FCStone Inc. common stockholders	$ 0.00	$ 0.00	$ 0.00	$ 0.01
Net income attributable to INTL FCStone Inc. common stockholders	$ 0.23	$ 0.55	$ 0.33	$ 1.57
Weighted-average number of common shares outstanding:
Basic	18,392,823	17,901,613	18,286,308	17,714,916
Diluted	19,098,667	19,280,696	19,156,471	19,308,661
Amounts attributable to INTL FCStone Inc. common stockholders:
Income from continuing operations, net of tax	4.7	10.4	6.7	29.6
Income from discontinued operations, net of tax	0	0	0	0.2
Net income	$ 4.7	$ 10.4	$ 6.7	$ 29.8