Condensed Consolidated Cash Flows Statements Statement (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 13.3	$ (0.5)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	1.8	1.5
Provision for bad debts and impairments	0.4	0.1
Deferred income taxes	(0.4)	(0.6)
Amortization of debt issuance costs and debt discount	0.3	0.4
Amortization of stock-based compensation expense	1.6	1.0
Gain (Loss) on Sale of Other Assets	(9.2)	0
Changes in operating assets and liabilities, net:
Cash, securities and other assets segregated under federal and other regulations	(24.2)	(354.7)
Deposits and receivables from exchange-clearing organizations	141.1	473.6
Deposits and receivables from broker-dealers, clearing organizations, and counterparties	1.4	11.9
Receivable from customers, net	(75.2)	25.7
Notes receivable from customers, net	13.7	6.0
Income taxes receivable	4.2	(0.3)
Financial instruments owned and securities purchased under agreements to resell, at fair value	11.6	76.6
Physical commodities inventory	(2.3)	47.0
Other assets	(2.0)	4.2
Accounts payable and other accrued liabilities	(20.0)	(7.3)
Payable to customers	(8.0)	(99.3)
Payable to broker-dealers, clearing organizations and counterparties	(31.8)	11.8
Income taxes payable	0.8	0.4
Financial instruments sold, not yet purchased, at fair value	12.1	(164.4)
Net cash provided by (used in) operating activities	29.2	33.1
Cash flows from investing activities:
Deconsolidation of affiliates	0	0.4
Cash paid for other acquisitions, net	0	(1.0)
Sale of exchange memberships and common stock	10.1	0
Purchase of property and equipment	(1.2)	(3.2)
Net cash used in investing activities	8.9	(3.8)
Cash flows from financing activities:
Net change in payable to lenders under loans and overdrafts	23.2	38.5
Payments related to earn-outs on acquisitions	(0.3)	(0.3)
Exercise of stock options	0	0.3
Share repurchase	(2.0)	0
Income tax benefit on stock options and awards	(0.3)	0
Net cash provided by financing activities	20.6	38.5
Effect of exchange rates on cash and cash equivalents	(0.3)	(0.1)
Net increase (decrease) in cash and cash equivalents	58.4	67.7
Cash and cash equivalents at beginning of period	236.3	220.6
Cash and cash equivalents at end of period	294.7	288.3
Supplemental disclosure of cash flow information:
Cash paid for interest	2.5	2.1
Income taxes paid, net of cash refunds	1.3	1.4
Supplemental disclosure of non-cash investing and financing activities:
Identified intangible assets and goodwill on acquisitions	3.1	1.2
Additional consideration payable related to acquisitions	$ 3.4	$ 0.9