Quarterly Financial Information (Unaudited) (Tables)

12 Months Ended

Sep. 30, 2015

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

The Company has set forth certain quarterly unaudited financial data for the past two years in the tables below:

	For the 2015 Fiscal Quarter Ended
(in millions, except per share amounts)	September 30		June 30		March 31		December 31
Total revenues	$	2,628.4	$	3,995.1	$	14,442.0	$	13,627.7
Cost of sales of physical commodities	2,449.7		3,843.5		14,285.5		13,490.2
Operating revenues	178.7		151.6		156.5		137.5
Transaction-based clearing expenses	31.3		30.2		31.8		29.4
Introducing broker commissions	15.1		13.1		12.3		12.2
Interest expense	5.0		4.9		4.5		2.7
Net operating revenues	127.3		103.4		107.9		93.2
Compensation and other expenses	98.1		86.2		89.8		79.6
Income from continuing operations, before tax	29.2		17.2		18.1		13.6
Income tax expense	8.1		5.0		5.1		4.2
Net income	$	21.1	$	12.2	$	13.0	$	9.4
Net basic earnings per share	$	1.12	$	0.64	$	0.68	$	0.50
Net diluted earnings per share	$	1.09	$	0.62	$	0.67	$	0.49

	For the 2014 Fiscal Quarter Ended
(in millions, except per share amounts)	September 30		June 30			March 31			December 31
Total revenues	$	10,655.7	$	7,005.1		$	8,452.9		$	7,908.7
Cost of sales of physical commodities	10,525.1		6,886.9			8,323.7			7,795.8
Operating revenues	130.6		118.2			129.2			112.9
Transaction-based clearing expenses	27.5		28.1			27.7			25.2
Introducing broker commissions	13.9		11.6			12.8			11.6
Interest expense	2.5		2.5			2.8			2.7
Net operating revenues	86.7		76.0			85.9			73.4
Compensation and other expenses	78.9		72.0			75.6			69.5
(Loss) income from continuing operations, before tax	7.8		4.0			10.3			3.9
Income tax (benefit) expense	2.0		0.3			2.6			1.5
Income from continuing operations	5.8		3.7			7.7			2.4
(Loss) income from discontinued operations, net of tax	—		(0.2		)	(0.2		)	0.1
Net income	$	5.8	$	3.5		$	7.5		$	2.5
Net basic earnings per share	$	0.30	$	0.19		$	0.39		$	0.13
Net diluted earnings per share	$	0.29	$	0.18		$	0.39		$	0.12