Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Mar. 31, 2012	Mar. 26, 2011
Income Taxes [Line Items]
Decrease in valuation allowance	$ 39,300,000	$ 157,800,000
Forecasting period for realizing deferred tax assets	3 years	3 years
Federal net operating loss carryforwards	353,800,000
Net operating loss included in deferred tax assets	105,220,000	131,331,000
Excess stock deductions	77,800,000
Unrecognized tax benefit	0	0
Section 382 Of Internal Revenue Code [Member]
Income Taxes [Line Items]
Federal net operating loss carryforwards	36,600,000
Federal [Member]
Income Taxes [Line Items]
Net operating loss included in deferred tax assets	276,000,000
Tax effected deferred tax asset	96,600,000
Non-U.S [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	2,100,000
Undistributed earnings in non-U.S subsidiaries	185,000
Unrecognized tax benefit	66,000
State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	104,800,000
Maximum [Member] | Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforward expirations	2029
Maximum [Member] | State [Member]
Income Taxes [Line Items]
Net operating loss carryforward expirations	2029
Minimum [Member] | Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforward expirations	2019
Minimum [Member] | State [Member]
Income Taxes [Line Items]
Net operating loss carryforward expirations	2013
Research Tax Credit Carryforward [Member] | Federal [Member]
Income Taxes [Line Items]
Tax credit carryforward	21,400,000
Research Tax Credit Carryforward [Member] | State [Member]
Income Taxes [Line Items]
Tax credit carryforward	14,600,000
Tax credit carryforward subject to expiration	2,900,000
Tax credit carryforward not subject to expiration	$ 11,700,000
Research Tax Credit Carryforward [Member] | Maximum [Member] | Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforward expirations	2032
Research Tax Credit Carryforward [Member] | Maximum [Member] | State [Member]
Income Taxes [Line Items]
Net operating loss carryforward expirations	2027
Research Tax Credit Carryforward [Member] | Minimum [Member] | Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforward expirations	2013
Research Tax Credit Carryforward [Member] | Minimum [Member] | State [Member]
Income Taxes [Line Items]
Net operating loss carryforward expirations	2022