Assets and Liabilities, at Fair Value Assets and Liabilities, at Fair Value (Tables)

3 Months Ended

Dec. 31, 2012

Assets and Liabilities, at Fair Value [Abstract]

Schedule of Fair Value, Assets and Liabilities 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 December 31, 2012 and September 30, 2012 by level within the fair value hierarchy.

	December 31, 2012
(in millions)	Level 1		Level 2		Level 3		Netting and Collateral (1)			Total
Assets:
Money market funds	$	0.1	$	—	$	—	$	—		$	0.1
Certificate of deposits	6.4		—		—		—			6.4
Unrestricted cash equivalents	6.5		—		—		—			6.5
Commodities warehouse receipts	18.4		—		—		—			18.4
U.S. government obligations	—		23.0		—		—			23.0
Securities and other assets segregated under federal and other regulations	18.4		23.0		—		—			41.4
Money market funds	731.8		—		—		—			731.8
U.S. government obligations	—		701.2		—		—			701.2
Mortgage-backed securities	—		6.5		—		—			6.5
Derivatives	1,950.8		—		—		(1,960.1		)	(9.3		)
Deposits and receivables from exchange-clearing organizations	2,682.6		707.7		—		(1,960.1		)	1,430.2
Deposits and receivables from broker-dealers, clearing organizations and counterparties - derivatives	0.8		—		—		4.0			4.8
Common and preferred stock and American Depositary Receipts ("ADRs")	27.9		17.3		0.9		—			46.1
Exchangeable foreign ordinary equities and ADRs	18.2		—		—		—			18.2
Corporate and municipal bonds	—		—		3.6		—			3.6
U.S. government obligations	—		0.3		—		—			0.3
Foreign government obligations	11.2		—		—		—			11.2
Derivatives	192.9		604.3		—		(746.9		)	50.3
Commodities leases	—		45.1		—		(34.8		)	10.3
Commodities warehouse receipts	5.3		—		—		—			5.3
Exchange firm common stock	3.0		0.4		—		—			3.4
Mutual funds and other	2.4		—		—		—			2.4
Financial instruments owned	260.9		667.4		4.5		(781.7		)	151.1
Total assets at fair value	$	2,969.2	$	1,398.1	$	4.5	$	(2,737.8	)	$	1,634.0
Liabilities:
Accounts payable and other accrued liabilities - contingent liabilities	$	—	$	—	$	17.9	$	—		$	17.9
Payables to exchange-clearing organizations, broker-dealers and counterparties - derivatives	1,702.5		—		—		(1,702.5		)	—
Common and preferred stock and ADRs	40.3		14.9		—		—			55.2
Exchangeable foreign ordinary equities and ADRs	6.2		—		—		—			6.2
Derivatives	199.4		591.6		—		(754.2		)	36.8
Commodities leases	—		308.4		—		(219.1		)	89.3
Financial instruments sold, not yet purchased	245.9		914.9		—		(973.3		)	187.5
Total liabilities at fair value	$	1,948.4	$	914.9	$	17.9	$	(2,675.8	)	$	205.4

(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.

	September 30, 2012
(in millions)	Level 1		Level 2		Level 3		Netting and Collateral (1)			Total
Assets:
Money market funds	$	0.1	$	—	$	—	$	—		$	0.1
Certificate of deposits	10.4		—		—		—			10.4
Unrestricted cash equivalents	10.5		—		—		—			10.5
Commodities warehouse receipts	22.3		—		—		—			22.3
U.S. government obligations	—		50.5		—		—			50.5
Securities and other assets segregated under federal and other regulations	22.3		50.5		—		—			72.8
Money market funds	335.1		—		—		—			335.1
U.S. government obligations	—		1,318.3		—		—			1,318.3
Mortgage-backed securities	—		7.0		—		—			7.0
Derivatives	3,344.3		—		—		(3,494.7		)	(150.4		)
Deposits and receivables from exchange-clearing organizations	3,679.4		1,325.3		—		(3,494.7		)	1,510.0
Deposits and receivables from broker-dealers, clearing organizations and counterparties - derivatives	0.7		5.0		—		(6.4		)	(0.7		)
Common and preferred stock and American Depositary Receipts ("ADRs")	17.8		5.6		0.9		—			24.3
Exchangeable foreign ordinary equities and ADRs	10.0		—		—		—			10.0
Corporate and municipal bonds	0.3		0.6		3.6		—			4.5
U.S. government obligations	—		0.3		—		—			0.3
Foreign government obligations	14.8		—		—		—			14.8
Derivatives	315.6		785.3		—		(1,047.0		)	53.9
Commodities leases	—		135.2		—		(93.1		)	42.1
Commodities warehouse receipts	7.5		—		—		—			7.5
Exchange firm common stock	3.4		9.0		—		—			12.4
Mutual funds and other	1.9		—		—		—			1.9
Financial instruments owned	371.3		936.0		4.5		(1,140.1		)	171.7
Total assets at fair value	$	4,084.2	$	2,316.8	$	4.5	$	(4,641.2	)	$	1,764.3
Liabilities:
Accounts payable and other accrued liabilities - contingent liabilities	$	—	$	—	$	14.8	$	—		$	14.8
Payables to exchange-clearing organizations, broker-dealers and counterparties - derivatives	3,562.3		—		—		(3,562.3		)	—
Common and preferred stock and ADRs	16.4		5.9		—		—			22.3
Exchangeable foreign ordinary equities and ADRs	5.7		—		—		—			5.7
Derivatives	338.1		775.2		—		(1,068.7		)	44.6
Commodities leases	—		220.0		—		(117.2		)	102.8
Financial instruments sold, not yet purchased	360.2		1,001.1		—		(1,185.9		)	175.4
Total liabilities at fair value	$	3,922.5	$	1,001.1	$	14.8	$	(4,748.2	)	$	190.2

(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 and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

Information on Level 3 Financial Assets and Liabilities

The Company’s financial assets at fair value classified within level 3 of the fair value hierarchy as of December 31, 2012 and September 30, 2012 are summarized below:

(in millions)	December 31, 2012			September 30, 2012
Total level 3 assets	$	4.5		$	4.5
Level 3 assets for which the Company bears economic exposure	$	4.5		$	4.5
Total assets	$	2,939.6		$	2,958.9
Total financial assets at fair value	$	1,634.0		$	1,764.3
Total level 3 assets as a percentage of total assets	0.2		%	0.2		%
Level 3 assets for which the Company bears economic exposure as a percentage of total assets	0.2		%	0.2		%
Total level 3 assets as a percentage of total financial assets at fair value	0.3		%	0.3		%

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 three months ended December 31, 2012 and 2011, including a summary of unrealized gains (losses) during the respective periods on the Company’s level 3 financial assets and liabilities still held as of December 31, 2012.

	Level 3 Financial Assets and Financial Liabilities For the Three Months Ended December 31, 2012
(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:
Common stock and ADRs	$	0.9	$	—	$	—	$	—	$	—		$	—	$	0.9
Corporate and municipal bonds	3.6		—		—		—		—			—		3.6
	$	4.5	$	—	$	—	$	—	$	—		$	—	$	4.5
Liabilities:
Contingent liabilities	$	14.8	$	—	$	0.3	$	3.1	$	(0.3	)	$	—	$	17.9

	Level 3 Financial Assets and Financial Liabilities For the Three Months Ended December 31, 2011
(in millions)	Balances at beginning of period		Realized gains (losses) during period		Unrealized gains (losses) during period			Settlements			Transfers in or (out) of Level 3		Balances at end of period
Assets:
Common stock and ADRs	$	1.1	$	—	$	—		$	—		$	—	$	1.1
Corporate and municipal bonds	3.6		—		(0.1		)	—			—		3.5
Mutual funds and other	0.4		—		—			—			—		0.4
	$	5.1	$	—	$	(0.1	)	$	—		$	—	$	5.0
Liabilities:
Contingent liabilities	$	22.3	$	—	$	0.9		$	(0.3	)	$	—	$	22.9

Available-for-sale Securities [Table Text Block]

The Company has recorded unrealized gains, net of income tax expense, related to U.S. government obligations and corporate bonds classified as available-for-sale securities in other comprehensive income ("OCI") as of December 31, 2012. The following tables summarize the amortized cost basis, the aggregate fair value and gross unrealized holding gains and losses of the Company’s investment securities classified as available-for-sale as of December 31, 2012 and September 30, 2012:

December 31, 2012
Amounts included in deposits with and receivables from exchange-clearing organizations:
	Amortized Cost		Unrealized Holding (1)				Estimated Fair Value
(in millions)			Gains		(Losses)
U.S. government obligations	$	654.1	$	—	$	—	$	654.1
Mortgage-backed securities	6.4		0.1		—		6.5
	$	660.5	$	0.1	$	—	$	660.6

(1) Unrealized gain/loss on U.S. government obligations as of December 31, 2012, is less than 0.1 million.

September 30, 2012
Amounts included in deposits with and receivables from exchange-clearing organizations:
	Amortized Cost		Unrealized Holding (1)				Estimated Fair Value
(in millions)			Gains		(Losses)
U.S. government obligations	$	1,298.9	$	—	$	—	$	1,298.9
Mortgage-backed securities	6.8		0.1		—		6.9
	$	1,305.7	$	0.1	$	—	$	1,305.8

(1) Unrealized gain/loss on U.S. government obligations as of September 30, 2012, is less than 0.1 million.

As of December 31, 2012 and September 30, 2012, investments in debt securities classified as available-for-sale ("AFS") mature as follows:

December 31, 2012
	Due in				Estimated Fair Value
(in millions)	Less than 1 year		1 year or more
U.S. government obligations	$	654.1	$	—	$	654.1
Mortgage-backed securities	—		6.5		6.5
	$	654.1	$	6.5	$	660.6

September 30, 2012
	Due in				Estimated Fair Value
(in millions)	Less than 1 year		1 year or more
U.S. government obligations	$	1,298.9	$	—	$	1,298.9
Mortgage-backed securities	—		6.9		6.9
	$	1,298.9	$	6.9	$	1,305.8

There were no sales of AFS securities during the three months ended December 31, 2012 and 2011, and as a result, no realized gains or losses were recorded for the three months ended December 31, 2012 and 2011.

For the purposes of the maturity schedule, mortgage-backed securities, which are not due at a single maturity date, have been allocated over maturity groupings based on the expected maturity of the underlying collateral. Mortgage-backed securities may mature earlier than their stated contractual maturities because of accelerated principal repayments of the underlying loans.

The Company has also classified equity investments in exchange firms' common stock not pledged for clearing purposes as available-for-sale. The investments are recorded at fair value, with unrealized gains and losses recorded, net of taxes, as a component of OCI until realized. As of December 31, 2012, the cost and fair value of all the equity investments in exchange firms was $4.0 million and $3.4 million, respectively.

In June 2012, the board of LME Holdings Limited, the parent company of The London Metal Exchange (LME), entered into a framework agreement regarding the terms of a recommended cash offer for the entire issued and outstanding ordinary share capital of LME Holdings. In July 2012, the shareholders of LME Holdings voted to approve the sale of LME Holdings to the Hong Kong Exchanges & Clearing Limited. In December 2012, the Company received proceeds of $8.6 million from the sale of its shares in the LME. The shares of the LME were previously held by the Company as available-for-sale and the unrealized gain for those shares was reflected in OCI. For the three months ended December 31, 2012, the Company reclassified the unrealized gain remaining in accumulated OCI of approximately $6.3 million, net of income tax expense of $2.0 million, into the current period earnings.

The Company recorded unrealized losses of $0.4 million, net of income tax benefit of $0.2 million in OCI related to the remaining equity investments in exchange firms as of December 31, 2012. The Company monitors the fair value of exchange common stock on a periodic basis, and does not consider any current unrealized losses to be anything other than a temporary impairment.