Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Significant Accounting Policies

Schedule of client commission arrangement

Client commissions allocated for research and related prepaid and accrued research balances for the years ended December 31, 2012, 2011 and 2010 were as follows (dollars in millions):

	2012			2011			2010
Client commissions	$	112.1		$	130.8		$	155.8
Prepaid research, gross	$	5.1		$	3.7		$	4.6
Allowance for prepaid research		(0.4	)		(0.4	)		(0.4	)
Prepaid research, net of allowance	$	4.7		$	3.3		$	4.2
Accrued research payable	$	38.6		$	50.7		$	41.6

Summary of weighted average assumptions used for grants

	2011			2010
Dividend yield		0.0	%		0.0	%
Risk free interest rate		2.0	%		1.5	%
Expected volatility		40	%		44	%
Expected life (years)		4.76			4.00