Condensed Consolidated Cash Flows Statements - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Assets acquired	$ 40.9	$ 0.0
Escrow deposits related to acquisitions	2.5	0.0
Liabilities assumed	(7.7)	0.0
Cash flows from operating activities:
Net income	57.9	39.8
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	9.6	8.4
Bad debts	1.5	1.9
(Recovery) bad debt on physical coal	(2.4)	1.0
Deferred income taxes	0.3	19.7
Amortization of debt issuance costs	1.2	0.8
Amortization of stock-based compensation	5.9	4.9
Bargain purchase gain on acquisition	(5.4)	0.0
Changes in operating assets and liabilities, net:
Securities and other assets segregated under federal and other regulations	584.4	(657.0)
Securities purchased under agreements to resell	(662.2)	(363.4)
Securities borrowed	(948.6)	(89.7)
Deposits with and receivables from broker-dealers, clearing organizations, and counterparties	(238.7)	(622.0)
Receivables from clients, net	5.9	22.5
Notes receivable, net	(0.6)	(0.4)
Income taxes receivable	(0.6)	(0.8)
Financial instruments owned, at fair value	(368.0)	(254.0)
Physical commodities inventory, net	(115.5)	(89.0)
Other assets	(7.8)	1.5
Accounts payable and other accrued liabilities	(4.0)	1.5
Payables to customers	(7.3)	319.7
Payables to broker-dealers, clearing organizations and counterparties	100.9	10.0
Income taxes payable	1.8	6.4
Securities sold under agreements to repurchase	964.0	206.0
Securities loaned	963.0	93.2
Financial instruments sold, not yet purchased, at fair value	(9.7)	294.2
Net cash used in operating activities	325.6	(1,044.8)
Cash flows from investing activities:
Cash paid for acquisitions, net	(28.0)	0.0
Purchase of property and equipment	(10.3)	(9.3)
Net cash used in investing activities	(38.3)	(9.3)
Cash flows from financing activities:
Net change in payable to lenders under loans	(16.9)	131.0
Proceeds from issuance of senior secured term loan	175.0	0.0
Repayment of senior unsecured notes	(4.4)	0.0
Payments of note payable	(0.6)	(0.6)
Deferred payments on acquisitions	0.0	(5.5)
Debt issuance costs	(3.3)	(0.4)
Proceeds from Stock Options Exercised	0.8	2.6
Withholding taxes on stock option exercises	0.0	(0.8)
Net cash provided by financing activities	150.6	126.3
Effect of exchange rates on cash and cash equivalents	0.6	3.0
Net (decrease) increase in cash and cash equivalents	438.5	(924.8)
Cash, segregated cash, cash equivalents, and segregated cash equivalents at beginning of period	2,628.6	1,676.6
Supplemental disclosure of cash flow information:
Cash paid for interest	110.1	54.2
Income taxes paid, net of cash refunds	17.5	15.8
Supplemental disclosure of non-cash investing and financing activities:
Identified intangible assets and goodwill on acquisitions	2.7	0.0
Total net assets acquired	$ 33.2	$ 0.0