QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details Textuals) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Jul. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Jan. 31, 2011
Aggregate tax benefit	$ 0.9		$ 0.9
Income tax credit for qualified research and development activities per basic and diluted share (in dollars per share)				$ 0.02
Income tax credit from tax related item			2.0
Income tax credit from tax related item per basic and diluted share	$ 0.02		$ 0.04
Impact of impairment losses on intangible assets in net income attributable to parent, Amount		2.4
Impact of impairment losses on intangible assets in net income attributable to parent, per basic share (in dollars per share)		$ 0.05
Net Income Impact From Research And Development Credits Net Of Expenses				$ 0.8
Aggregate Diluted Earnings Per Share Impact From Impairment Losses		$ 0.04