Discontinued Operations - Discontinued Operations Related to Securities Clearing Business (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Discontinued Operations And Disposal Groups [Abstract]
Revenues
Loss from discontinued operations, before tax benefit
Income tax benefit
Net loss from discontinued operations, before impairment of assets
Net loss on impairment of assets of discontinued operations net of tax benefit in the three and nine months ended March 31, 2012 of $1.0 and $1.0, respectively		(1.4)		(1.4)
Loss from discontinued operations, net of tax benefit		$ (1.4)		$ (1.4)