Assets and Liabilities, at Fair Value (Tables)

12 Months Ended

Sep. 30, 2018

Assets and Liabilities, at Fair Value [Abstract]

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

The following tables set forth the Company’s financial and nonfinancial assets and liabilities accounted for at fair value, on a recurring basis, as of September 30, 2018 and September 30, 2017 by level in the fair value hierarchy. There were no assets or liabilities that were measured at fair value on a nonrecurring basis as of September 30, 2018 and 2017.



	September 30, 2018
(in millions)	Level 1		Level 2		Level 3		Netting ⁽¹⁾			Total
Assets:
Certificates of deposit	$	3.8	$	—	$	—	$	—		$	3.8
Unrestricted cash equivalents - certificates of deposit	3.8		—		—		—			3.8
Commodities warehouse receipts	42.9		—		—		—			42.9
U.S. Treasury obligations	600.4		—		—		—			600.4
Securities and other assets segregated under federal and other regulations	643.3		—		—		—			643.3
U.S. Treasury obligations	778.4		—		—		—			778.4
“To be announced” (TBA) and forward settling securities	—		5.0		—		(2.1		)	2.9
Foreign government obligations	7.7		—		—		—			7.7
Derivatives	7,495.9		19.6		—		(7,787.1		)	(271.6		)
Deposits with and receivables from broker-dealers, clearing organizations and counterparties	8,282.0		24.6		—		(7,789.2		)	517.4
Equity securities	71.2		3.0		—		—			74.2
Corporate and municipal bonds	—		79.1		—		—			79.1
U.S. Treasury obligations	120.1		—		—		—			120.1
U.S. government agency obligations	—		472.9		—		—			472.9
Foreign government obligations	6.4		—		—		—			6.4
Agency mortgage-backed obligations	—		1,022.5		—		—			1,022.5
Asset-backed obligations	—		42.9		—		—			42.9
Derivatives	0.8		514.6		—		(329.3		)	186.1
Commodities leases	—		29.5		—		(11.8		)	17.7
Commodities warehouse receipts	16.4		—		—		—			16.4
Exchange firm common stock	10.2		—		—		—			10.2
Mutual funds and other	6.3		—		—		—			6.3
Financial instruments owned	231.4		2,164.5		—		(341.1		)	2,054.8
Physical commodities inventory	42.1		114.8		—		—			156.9
Total assets at fair value	$	9,202.6	$	2,303.9	$	—	$	(8,130.3	)	$	3,376.2
Liabilities:
Accounts payable and other accrued liabilities - contingent liabilities	$	—	$	—	$	—	$	—		$	—
TBA and forward settling securities	—		2.1		—		(2.1		)	—
Derivatives	7,809.3		11.6		—		(7,820.9		)	—
Payables to broker-dealers, clearing organizations and counterparties	7,809.3		13.7		—		(7,823.0		)	—
Equity securities	51.1		0.4		—		—			51.5
Corporate and municipal bonds	—		20.1		—		—			20.1
U.S. Treasury obligations	484.8		—		—		—			484.8
U.S government agency obligations	—		57.2		—		—			57.2
Agency mortgage-backed obligations	—		0.2		—		—			0.2
Derivatives	—		688.0		—		(494.6		)	193.4
Commodities leases	—		75.5		—		(16.2		)	59.3
Financial instruments sold, not yet purchased	535.9		841.4		—		(510.8		)	866.5
Total liabilities at fair value	$	8,345.2	$	855.1	$	—	$	(8,333.8	)	$	866.5


(1)	Represents cash collateral and the impact of netting across the levels of the fair value hierarchy. Netting among positions classified within the same level are included in that level.



	September 30, 2017
(in millions)	Level 1		Level 2		Level 3		Netting⁽¹⁾			Total
Assets:
Certificate of deposits	$	3.8	$	—	$	—	$	—		$	3.8
Unrestricted cash equivalents - certificates of deposits	3.8		—		—		—			3.8
Commodities warehouse receipts	21.0		—		—		—			21.0
U.S. Treasury obligations	33.5		—		—		—			33.5
Securities and other assets segregated under federal and other regulations	54.5		—		—		—			54.5
Foreign government obligations	—		6.4		—		—			6.4
U.S. Treasury obligations	244.7		—		—		—			244.7
TBA and forward settling securities	—		8.8		—		—			8.8
Derivatives	2,608.6		289.1		—		(2,952.9		)	(55.2		)
Deposits and receivables from broker-dealers, clearing organizations and counterparties	2,853.3		304.3		—		(2,952.9		)	204.7
Equity securities	40.4		4.6		0.1		—			45.1
Corporate and municipal bonds	28.2		0.9		—		—			29.1
U.S. Treasury obligations	60.0		—		—		—			60.0
U.S. government agency obligations	—		368.9		—		—			368.9
Foreign government obligations	—		10.2		—		—			10.2
Agency mortgage-backed obligations	—		920.9		—		—			920.9
Asset-backed obligations	—		47.3		—		—			47.3
Derivatives	1.3		1,413.4		—		(1,252.6		)	162.1
Commodities leases	—		174.1		—		(138.7		)	35.4
Commodities warehouse receipts	38.5		—		—		—			38.5
Exchange firm common stock	8.3		—		—		—			8.3
Mutual funds and other	6.0		—		—		—			6.0
Financial instruments owned	182.7		2,940.3		0.1		(1,391.3		)	1,731.8
Physical commodities inventory	73.2		—		—		—			73.2
Total assets at fair value	$	3,167.5	$	3,244.6	$	0.1	$	(4,344.2	)	$	2,068.0
Liabilities:
Accounts payable and other accrued liabilities - contingent liabilities	$	—	$	—	$	1.0	$	—		$	1.0
TBA and forward settling securities	—		4.9		—		(0.1		)	4.8
Derivatives	2,476.2		292.8		—		(2,769.0		)	—
Payable to broker-dealers, clearing organizations and counterparties - derivatives	2,476.2		297.7		—		(2,769.1		)	4.8
Equity securities	44.0		0.9		—		—			44.9
Corporate and municipal bonds	0.3		—		—		—			0.3
U.S. Treasury obligations	285.9		—		—		—			285.9
U.S government agency obligations	—		27.9		—		—			27.9
Agency mortgage-backed obligations	—		0.1		—		—			0.1
Derivatives	—		1,427.2		—		(1,110.2		)	317.0
Commodities leases	—		191.1		—		(149.6		)	41.5
Financial instruments sold, not yet purchased	330.2		1,647.2		—		(1,259.8		)	717.6
Total liabilities at fair value	$	2,806.4	$	1,944.9	$	1.0	$	(4,028.9	)	$	723.4


(1)	Represents cash collateral and the impact of netting across the levels of the fair value hierarchy. Netting among positions classified within the same level are included in that level.

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

The following tables set forth a summary of changes in the fair value of the Company’s Level 3 financial assets and liabilities during the fiscal years ended September 30, 2018 and 2017, including a summary of unrealized gains (losses) during the fiscal year ended on the Company’s Level 3 financial assets and liabilities held during the periods.



	Level 3 Financial Assets and Financial Liabilities For the Year Ended September 30, 2018
(in millions)	Balances at beginning of period		Realized gains (losses) during period		Unrealized gains (losses) during period			Purchases/ issuances		Settlements			Transfers in or (out) of Level 3		Balances at end of period
Assets:
Equity securities	$	0.1	$	—	$	(0.1	)	$	—	$	—		$	—	$	—

(in millions)	Balances at beginning of period		Realized (gains) losses during period		Remeasurement (gains) losses during period			Acquisitions		Settlements			Transfers in or (out) of Level 3		Balances at end of period
Liabilities:
Contingent liabilities	$	1.0	$	—	$	—		$	—	$	(1.0	)	$	—	$	—



	Level 3 Financial Assets and Financial Liabilities For the Year Ended September 30, 2017
(in millions)	Balances at beginning of period		Realized gains (losses) during period		Unrealized gains (losses) during period			Purchases/ issuances		Settlements			Transfers in or (out) of Level 3		Balances at end of period
Assets:
Equity securities	$	0.2	$	—	$	(0.1	)	$	—	$	—		$	—	$	0.1
Corporate and municipal bonds	3.0		—		—			—		(3.0		)	—		—
	$	3.2	$	—	$	(0.1	)	$	—	$	(3.0	)	$	—	$	0.1

(in millions)	Balances at beginning of period		Realized (gains) losses during period		Remeasurement (gains) losses during period			Acquisitions		Settlements			Transfers in or (out) of Level 3		Balances at end of period
Liabilities:
Contingent liabilities	$	0.8	$	—	$	0.2		$	—	$	—		$	—	$	1.0