Discontinued Operations and Assets Held For Sale (Details textual) (USD $)	6 Months Ended		3 Months Ended
	Sep. 30, 2012	Oct. 02, 2011	Oct. 02, 2011 Asset Purchase Agreement [Member]	Sep. 30, 2012 Synaptics asset purchase agreement [Member]	Aug. 01, 2012 Synaptics asset purchase agreement [Member] Employees	Jul. 01, 2012 Fixed Assets [Member]	Jul. 01, 2012 Intangible Assets [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Holding Period for Escrow Deposit			2 years
Cash held in escrow account related to divestiture			$ 6,000,000
Cash proceeds from sale	5,000,000	51,670,000	58,744,000	5,000,000
Gain (Loss) on divestiture			45,939,000	886,000
Assets Held-for-sale, Long Lived						$ 1,000,000	$ 700,000
Employees transferred to Synaptics					47