Condensed Consolidated Cash Flows Statements Statement (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net (loss) income	$ (0.5)	$ 4.0
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	1.5	1.0
Provision for bad debts and impairments	0.1	2.4
Deferred income taxes	(0.6)	0.8
Amortization of debt issuance costs and debt discount	0.4	0.1
Convertible debt interest settled in company stock upon conversion	0	0.1
Amortization of stock-based compensation expense	1.0	0.5
Gain on acquisition of INTL Provident	0	(0.4)
Changes in operating assets and liabilities, net:
Cash, securities and other assets segregated under federal and other regulations	(354.7)	(31.9)
Deposits and receivables from exchange-clearing organizations	473.6	(87.2)
Deposits and receivables from broker-dealers, clearing organizations, and counterparties	11.9	60.1
Receivable from customers, net	25.7	(3.1)
Notes receivable from customers, net	6.0	(29.7)
Income taxes receivable	(0.3)	1.5
Financial instruments owned and securities purchased under agreements to resell, at fair value	76.6	177.4
Physical commodities inventory	47.0	(28.7)
Other assets	4.2	(3.9)
Accounts payable and other accrued liabilities	(7.3)	4.9
Payable to customers	(99.3)	(94.0)
Payable to broker-dealers, clearing organizations and counterparties	11.8	4.3
Income taxes payable	0.4	(0.4)
Financial instruments sold, not yet purchased, at fair value	(164.4)	19.1
Net cash provided by (used in) operating activities	33.1	(3.1)
Cash flows from investing activities:
Deconsolidation of affiliates	0.4	0
Cash paid for other acquisitions, net	(1.0)	(9.3)
Purchase of securities purchased under agreements to resell	0	(62.3)
Purchase of exchange memberships and common stock	0	(0.4)
Purchase of property and equipment	(3.2)	(1.3)
Net cash used in investing activities	(3.8)	(73.3)
Cash flows from financing activities:
Net change in payable to lenders under loans and overdrafts	38.5	74.1
Payments related to earn-outs on acquisitions	(0.3)	0
Repayment of subordinated debt	0	(0.5)
Debt issuance costs	0	(1.2)
Exercise of stock options	0.3	0.1
Net cash provided by financing activities	38.5	72.5
Effect of exchange rates on cash and cash equivalents	(0.1)	0
Net increase (decrease) in cash and cash equivalents	67.7	(3.9)
Cash and cash equivalents at beginning of period	220.6	81.9
Cash and cash equivalents at end of period	288.3	78.0
Supplemental disclosure of cash flow information:
Cash paid for interest	2.1	2.0
Income taxes paid, net of cash refunds	1.4	1.2
Supplemental disclosure of non-cash investing and financing activities:
Conversion of subordinated notes to common stock, net	0	5.6
Identified intangible assets and goodwill on acquisitions	1.2	0
Additional consideration payable related to acquisitions	$ 0	$ 3.7