Other Non-Current Assets (Narrative) (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Other Noncurrent Assets [Line Items]
Deferred client conversion and start-up costs	$ 115.9	$ 125.8
Deferred Costs	47.2
Note receivable from PWI		20.6
Impairment charge on note receivable	21.4
Accrued interest	0.8
Number of PWI common shares received in connection with disposal of discontinued operations	2,455,627
Other-than-temporary impairment charge	12.5
Penson Worldwide, Inc. [Member]
Other Noncurrent Assets [Line Items]
Deferred client conversion and start-up costs	$ 47.2