Commitments and Contingencies (Details Textuals) (USD $) In Millions	3 Months Ended	12 Months Ended
	Oct. 31, 2009	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009	Apr. 30, 2010	Jan. 31, 2010
Commitments and Contingencies (Textuals) [Abstract]
Payment as part of settlement agreement to Motorola	$ 19.8
Litigation Reserve					1.7	0.5
Lease Rental Expenses		4.5	3.1	3.0
Hardware Warranty Period		12-15 months from the date of purchase
Software Warranty Period		90 days from the date the products are delivered to the end customer
Non Cancelable Purchase commitments		29.7	20.3
Payments for settlement of claims or defend lawsuits pursuant to indemnifications		0
Indemnification liability		$ 0	$ 0